- 0 -lss.bao.ac.cn/meeting/cosmo12/image/COSMO12_abstract...Hu Zhan (NAOC, Co-chair) Pengjie Zhang...

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Contents

Organizations and Committees .................................................... 2

Venues and Maps ......................................................................... 4

Program ........................................................................................ 6

Plenary Sessions ...................................................................................... 7

Parallel Sessions .................................................................................... 10

Abstract ....................................................................................... 19

Plenary Sessions .................................................................................... 19

Parallel Sessions .................................................................................... 31

String Cosmology ............................................................................................... 32

Inflation ............................................................................................................... 34

Session 1………………………………………………………………..…………….34

Session 2……………………………………………………………………...………36

Session 3……………………………………………………………………..……….41

Dark Matter and Relics ........................................................................................ 45

Session 1……………………………………………………………………..……….45

Session 2………………………………………………………………………...……50

Cosmic Acceleration ............................................................................................ 54

Session 1…………………………………………………………………………..….54

Session 2…………………………………………………………………………..….57

Cosmic Probes ..................................................................................................... 61

Session 1………………………………………………………………………….…..61

Session 2………………………………………………………………………….…..64

Cosmic Microwave Background ......................................................................... 69

List of Participants ...................................................................... 71

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Organized and Supported by

NSFC - National Natural Science Foundation of China

CAS - Chinese Academy of Sciences

NAOC - National Astronomical Observatories, CAS

ITP/KITPC - Institute of Theoretical Physics & Kavli Institute for

Theoretical Physics China, CAS

IHEP - Institute of High Energy Physics, CAS

SHAO - Shanghai Astronomical Observatory, CAS

CCAST - China Center of Advanced Science and Technology

THU - Tsinghua University

SJTU - Shanghai Jiao Tong University

PKU - Peking University

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Scientific Organizing Committee

Andreas Albrecht (UC Davis)

Pisin Chen (LeCosPA, National Taiwan Univ.)

Carlos Frenk (Durham Univ.)

Jihn Kim (Seoul National Univ.)

Rocky Kolb (Univ. of Chicago)

Hitoshi Murayama (IPMU, Univ. of Tokyo)

Leszek Roszkowski (NCNR,

Warsaw/Sheffield)

Charling Tao (Tsinghua Univ. & IN2P3)

Hu Zhan (NAOC)

Xinmin Zhang (IHEP, Chair)

Local Organizing Committee

Xiaojun Bi (IHEP)

Ronggen Cai (ITP, Co-chair)

Xuelei Chen (NAOC)

Liang Gao (NAOC)

Qingguo Huang (ITP)

Miao Li (ITP)

Kaixuan Ni (SJTU)

Yunsong Piao (UCAS)

Hu Zhan (NAOC, Co-chair)

Pengjie Zhang (SHAO)

Yufeng Zhou (ITP)

COSMO Steering Committee

Leszek Roszkowski (NCNR,

Warsaw/Sheffield, Chair)

Vernon Barger (Wisconsin)

John Beacom (Ohio State)

David Caldwell (Stanford)

Sean Carroll (Caltech)

Manuel Drees (Bonn)

Jonathan Ellis (CERN)

Kari Enqvist (Helsinki)

Joshua Frieman (Fermilab)

Evalyn Gates (Chicago)

Ruth Gregory (Durham)

Francis Halzen (Wisconsin)

Stephen Hawking (Cambridge)

Mark Hindmarsh (Sussex)

Stavros Katsanevas (Paris)

Jihn Kim (Seoul)

Lloyd Knox (UC Davis)

Rocky Kolb (Chicago)

Julien Lesgourgues (CERN)

Andrei Linde (Stanford)

David Lyth (Lancaster)

Carlos Martins (Porto)

Hans-Peter Nilles (Bonn)

Michael Ramsey-Musolf (Wisconsin)

Antonio Riotto (CERN)

Matts Roos (Helsinki)

Graham Ross (Oxford)

Goran Senjanovic (ICTP)

Jun'ichi Yokoyama (RESCEU, Tokyo)

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Venues

All plenary (morning) sessions will be held at the University of Chinese

Academy of Sciences (UCAS, Zhong Guan Cun campus).

Parallel (afternoon) sessions will be held at UCAS and the Kavli

Institute for Theoretical Physics China (KIPTC). The KITPC building is

to the north of UCAS campus, across the street.

UCAS Address

No. 80 Zhong Guan Cun E. Rd, Haidian Dist., Beijing 100190

KITPC Address

No. 55 Zhong Guan Cun E. Rd, Haidian Dist., Beijing 100190

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Program

Sunday, Sept. 9, KITPC 3rd Floor Lobby

14:00--18:30 Registration

18:30--20:00 Reception

Monday, Sept. 10

Plenary Session (UCAS S201, Chair: Zhao-Xi Zhang)

9:00--9:10 Welcome Speech by UCAS Vice President Gang Su

9:10--9:20 Opening Remarks by COSMO Steering Cmte Chair Leszek

Roszkowski

9:20--10:00 Dark Matter & Dark Energy Projects and Progress in China

Yueliang Wu (UCAS/KITPC/ITP)

10:00--10:40 Inflation & Tests

Leonardo Senatore (Stanford)

10:40--11:10 Group Photo & Coffee Break

11:10--11:50 Astrophysical Evidence for Dark Matter

Joel Primack (UCSC)

11:50--12:30 Dark Matter Candidates

Paolo Gondolo (Utah)

Parallel Sessions

14:00--18:30

String Cosmology (14:00--16:00, UCAS S204)

Inflation (16:30--18:30, UCAS S204)

Dark Matter (KITPC 6620)

Cosmic Acceleration (14:00--16:00, UCAS S201)

Cosmic Probes (16:30--18:30, UCAS S201)

http://lss.bao.ac.cn/cosmo12/program.php?ses=11





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Tuesday, Sept. 11

Plenary Session (UCAS S101, Chair: Leszek Roszkowski)

9:00--9:40 Recent Results from the Large Hadron Collider

Markus Elsing (CERN)

9:40--10:20 Eternal Inflation, and How It Ends

Matt Kleban (NYU)

10:20--10:50 Coffee Break

10:50--11:30 CMB Science in the Post-WMAP Era

Scott Dodelson (Chicago)

11:30--12:10 Axion or Axino Dark Matter in String Axiverse Scenario

Kiwoon Choi (KAIST)

Parallel Sessions

14:00--18:30

Inflation (UCAS S101)

Dark Matter (KITPC 6620)

Cosmic Acceleration (UCAS S201)

Cosmic Microwave Background (14:00--15:40, KITPC 6420)

Wednesday, Sept. 12

Plenary Session (UCAS S101, Chair: Congfeng Qiao)

9:00--9:40 Dark Energy Research in China

Zuhui Fan (PKU)

9:40--10:20 Modified Gravity and Cosmology

Pedro Ferreira （Oxford)


10:50--11:30 Baryo/Leptogenesis

Mikhail Shaposhnikov (EPFL)

11:30--12:10 BBN and New Physics

Kazunori Kohri (KEK)

13:00--18:30 Excursion to the Great Wall. Bus leaving at 1pm from the UCAS gate.

18:45--20:45 Banquet at Beijing Friendship Hotel





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Thursday, Sept. 13

Plenary Session (UCAS S101, Chair: Rocky Kolb)

9:00--9:40 Inflation and Particle/String Model Building

Nemanja Kaloper (UC Davis)

9:40--10:20 Primordial Non-Gaussianity from Inflation

David Wands (Portsmouth)


10:50--11:30 Large-Scale Structure Observations & Simulations

Yipeng Jing (SHAO)

11:30--12:10 Cosmic Accleration Beyond Dark Energy

Albert Stebbins (Fermilab)

Parallel Sessions

14:00--18:30 Inflation (UCAS S101)

Cosmic Probes (UCAS S201)

Friday, Sept. 14

Plenary Session (UCAS S101, Chair: Charling Tao)

9:00--9:40 Recent Neutrino Oscillation Results and future

Jun Cao (IHEP)

9:40--10:20 Surveying Dark Energy

Eric Linder (Berkeley/LBNL/IEU)


10:50--11:30 Current and Future Constraints on Neutrinos from Large-Scale

Structure

Steen Hannestad (Aarhus Univ)

11:30--12:10 Testing Neutralino Dark Matter

Y-L Sming Tsai (NCNR, Warsaw)

12:10--12:30 Concluding Remarks By Rocky Kolb (Chicago)

12:30--12:40 COSMO Announcement by Leszek Roszkowski (NCNR,

Warsaw/Sheffield)



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Program/Parallel sessions

Monday, Sept. 10 String Cosmology UCAS S204 Chair: Matt Kleban

14:00--14:20 The tachyon unified model: a really universe-like brane

Huiquan Li (USTC)

14:20--14:40 Warped de Sitter solutions in the higher-dimensional gravity

Masato Minamitsuji (YITP)

14:40--15:00 Gravitational wave signals of extra dimensions

Ruth Gregory (Durham U.)

15:00--15:20 Gravitational Waves and Kaluza-Klein Modes from Cosmic

Super-Strings

Jean-Francois Dufaux (APC, CNRS/U. Paris 7)

15:20--15:40 Correlation between cosmic strings, extra neutrino species and

gravity waves

Jon Urrestilla (U. Basque Country)

15:40--16:00 Forecast constraints on cosmic string parameters from

gravitational wave direct detection experiments

Koichi Miyamoto (ICRR, U. Tokyo)

Monday, Sept. 10 Inflation Session 1 UCAS S204 Chair: Shinji Mukohyama

16:30--16:50 Higgs Thermal Inflation and the Mu-Term

Mark Hindmarsh (U. Sussex)

16:50--17:10 Effective action for the Abelian Higgs model in an expanding

universe

Marieke Postma (Nikhef)

17:10--17:30 Non-Abelian Gauge Field Inflation

Azadeh Maleknejad (IPM)

17:30--17:50 No-boundary measure and preference of larger e-foldings by

multi-fields

Soo A Kim (APCTP)

17:50--18:10 A geometric bound on F-term inflation

Ivonne Zavala (U. Groningen)

18:10--18:30 A Cosmological Scenario without Initial Singularity

Taotao Qiu (LeCosPA, NTU)

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Monday, Sept. 10 Dark Matter & Relics Session 1 KITPC6620 Chair : Kaixuan Ni

14:00--14:20 Dark Matter Results from the XENON100 Experiment

Fei Gao (SJTU)

14:20--14:40 Strong Evidence for Gamma-ray Line Emission from the Inner Galaxy

Meng Su (Harvard/MIT)

14:40--15:00 A tentative gamma-ray line from dark matter annihilation at the Fermi

Large Area Telescoper

Christoph Weniger (MPI Physics, Munchen)

15:00--15:20 Remarks on two gamma ray lines from the inner galaxy

Ichiro Oda (U. Ryukyus)

15:20--15:40 What astrophysics and cosmology tell us about dark matter properties

Oleg Ruchayskiy (CERN)

15:40--16:00 Indirect dark matter searches in N-body simulations

Emmanuel Nezri


Chair: Xiaojun Bi

16:30--16:50 Detection of keV scale neutrino dark matter in the universe

Wei Liao (ECUST)

16:50--17:10 Exact Velocity Distributions of Galactic Dark Matter Halos in

Gamma-Ray Luminosity Calculations

Daniel Hunter (Washington U., St. Louis)

17:10--17:30 The gradient expansion as a model for non-linear clustering

Cornelius Rampf (RWTH Aachen)

17:30--17:50 The effect of quark interactions on dark matter kinetic decoupling and

the smallest dark halos

Kenji Kadota (Nagoya U.)

17:50--18:10 Primordial black hole formation from as axion-type curvaton model

Naoya Kitajima (U. Tokyo)

18:10--18:30 On the dissipation of the dark matter

Hermano Velten (Bielefeld U/UFES)

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Monday, Sept. 10 Cosmic Acceleration Session 1 UCAS S201 Chair: Albert Stebbins

14:00--14:20 Error Analysis of Ia Supernova and Query on Cosmic Dark Energy

Qiuhe Peng (Nanjing U.)

14:20--14:40 Testing General Relativity and LCDM with clusters of galaxies, the

CMB and galaxy clustering

David Rapetti (DARK, U. Copenhagen)

14:40--15:00 Observational tests of cosmic acceleration

Alireza Hojjati (Simon Fraser U.)

15:00--15:20 Chameleon cosmological constraints and degeneracies

Daniel Boriero (IFGW - UNICAMP)

15:20--15:40 Structure formation in a universe with dark energy clustering

Ole Bjaelde (Aarhus U.)

15:40--16:00 Cosmological constraints on the decomposed generalized

Chaplygin gas model

Yuting Wang (Dalian U. Tech./U. Portsmouth)

Monday, Sept. 10 Cosmic Probes Session 1 UCAS S201 Chair: Martin Kunz

16:30--16:50 21cm intensity mapping as a probe of cosmology

Xuelei Chen (NAOC)

16:50--17:10 Intensity Mapping of the [CII] Fine Structure Line during the

Epoch of Reionization

Yan Gong (UCI)

17:10--17:30 21cm radiation from minihalos as a probe of small primordial

non-Gaussianity

Siri Chongchitnan (Abertay Dundee)

17:30--17:50 Probing dark interactions

Valeria Pettorino (Geneva)

17:50--18:10 Neutrino properties from future galaxy surveys

Jan Hamann (Aarhus U.)

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Tuesday, Sept. 11 Inflation Session 2 UCAS S101 Chair: Yunsong Piao

14:00--14:20 Multiple Cosmic Collisions and the CMB

Jonathan Kozaczuk (UCSC)

14:20--14:40 Multiple Inflationary Stages with Varying Equation of State

Mohammad Hossein Namjoo (IPM/YITP)

14:40--15:00 Primordial black holes as a tool for constraining non-Gaussianity

Christian Byrnes (CERN)

15:00--15:20 Induced Gravitational Waves From Inflation

Laila Alabidi (YITP)

15:20--15:40 Gravitational waves produced by fermions

Tuukka Meriniemi (U. Helsinki)

15:40--16:00 Particle Production and Vacuum Selection with Higher Dimensional

Operator

Seishi Enomoto (Nagoya U.)


Chair: Gianmassimo Tasinato

16:30--16:50 Metric perturbation from inflationary magnetic field and generic bound

on inflation models

Teruaki Suyama (U. Tokyo)

16:50--17:10 Universal upper limit on inflation scale from cosmic magnetic field

Shinji Mukohyama (Kavli IPMU)

17:10--17:30 Uniqueness of the gauge invariant action for cosmological perturbations

Jan Weenink (Utrecht U.)

17:30--17:50 A backward formalism for multi-field inflation

Lingfei Wang (Lancaster U.)

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Tuesday, Sept. 11 Dark Matter & Relics Session 2 KITPC6620 Chair: Yufeng Zhou

14:00--14:20 Visible and dark matter from a first-order phase transition in a

baryon-symmetric universe

Raymond Volkas (U. Melbourne)

14:20--14:40 Affleck-Dine dynamics in gauge-mediated supersymmetry breaking

Kalliopi Petraki (U. Melbourne)

14:40--15:00 Neutrinos as the Origin of Dark and Baryonic Matter

Marco Drewes (Tech. U. Munchen)

15:00--15:20 Left-right symmetric model with a keV-scale dark matter candidate

Alexander Kartavtsev (MPI Nuclear Physics)

15:20--15:40 Bose-Einstein Condensate Dark Matter Phase Transition from the

Symmetry Breaking of λΦ^4 One-loop Contributions

Abril Suaez (Cinvestav)

15:40--16:00 Exact Solution to Finite Temperature SFDM: Natural Cores without

Feedback

Victor Hugo Robles Sanchez (Cinvestav IPN)


Chair: Mikhail Shaposhnikov

16:30--16:50 Evolution of magnetic fields, chiral anomalies and lepton asymmetry

Alexey Boyarsky (Leiden U.)

16:50--17:10 Electroweak Baryogenesis in the MSSM with light neutralinos

Germano Nardini (U. Bielefeld)

17:10--17:30 Non-Equilibrium Field Theory Approach to Leptogenesis

Bjorn Garbrecht (RWTH Aachen)

17:30--17:50 Temperature Dependence of Standard Model CP Violation

Olli Taanila (Bielefeld U.)

17:50--18:10 Axion production from topological defects

Ken'ichi Saikawa (ICRR, U. Tokyo)

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Tuesday, Sept. 11 Cosmic Acceleration Session 2 UCAS S201 Chair: David Rapetti

14:00--14:20 Self accelerating universe from non-linear massive gravity

Chunshan Lin (Kavli IPMU)

14:20--14:40 Nonlinear instability of homogeneous and isotropic solutions in massive

gravity

Emir Gumrukcuoglu (Kavli IPMU)

14:40--15:00 Massive Gravity on de Sitter and Unique Candidate for Partially

Massless Gravity

Sébastien Renaux-Petel (Inst. Lagrange, Paris)

15:00--15:20 Non-linear structure formation in a gradient expansion

Wessel Valkenburg (Leiden U.)

15:20--15:40 Vainshtein screening in a cosmological background in the most general

second-order scalar-tensor theory

Rampei Kimura (Hiroshima U.)

15:40--16:00 f(R) gravity and eV-mass sterile neutrinos

Hayato Motohashi (RESCEU, U. Tokyo)


Chair: Ronggen Cai

16:30--16:50 Nonlinear Perturbations in a Nonsingular Bounce

BingKan Xue (Princeton U.)

16:50--17:10 Natural Dark Energy from Lorentz Breaking

Blas Diego (CERN)

17:10--17:30 Cleaning up the cosmological constant

Antonio Padilla (U. Nottingham)

17:30--17:50 Disformally coupled quintessence

Tomi Koivisto (ITA, Oslo)

17:50--18:10 Cosmological pertrubations in k-essence model revised

Jiro Matsumoto (Nagoya U.)

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Tuesday, Sept. 11 CMB Session KITPC6420 Chair: Scott Dodelson

14:00--14:20 Second Order Perturbations of the CMB

Christian Fidler (ICG, U. Portsmouth)

14:20--14:40 Second order Boltzman code and CMB Bispectrum

Zhiqi Huang (CEA/Saclay)

14:40--15:00 Planck Era Black Hole Remnants and CMB Quadrupole Anomaly

Pisin Chen (LeCosPA, NTU)

15:00--15:20 Exploring the origin of the fine structures in the CMB temperature

angular power spectrum

Kohei Kumazaki (Nagoya U.)

15:20--15:40 Parity violation of gravitons in the CMB bispectrum

Maresuke Shiraishi (Nagoya U.)

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Thursday, Sept. 13 Inflation Session 3 UCAS S101 Chair: Qingguo Huang

14:00--14:20 Higgs condensation as an unwanted curvaton

Jun'ichi Yokoyama (RESCEU, U. Tokyo)

14:20--14:40 Curvaton induced modulated reheating

Osamu Seto (Hokkai-Gakuen U.)

14:40--15:00 Local non-Gaussianity from rapidly varying sound speeds

Jon Emery (ICG, U. Portsmouth)

15:00--15:20 Inhomogenous non-Gaussianity

Gianmassimo Tasinato (ICG, U. Portsmouth)

15:20--15:40 Strong scale dependent bispectrum in the Starobinsky model of

inflation

Frederico Arroja (IEU, Ewha Womans U.)

15:40--16:00 Observable non-gaussianity and gravity waves from particle

production during inflation

Ryo Namba (U. Minnesota)


Chair: Mark Hindmarsh

16:30--16:50 Anomalous High Energy Dependence in Inflationary Density

Perturbations

Yi Wang (McGill U.)

16:50--17:10 Influence of heavy modes on perturbations in multiple field inflation

Xian Gao (APC, U. Paris 7)

17:10--17:30 Investigation of multi-field DBI inflation

Taichi Kidani (ICG, U. Portsmouth)

17:30--17:50 Stochastic approach to flat and non-flat systems in inflationary

universe

Tomohiro Takesako (ICRR, U. Tokyo)

17:50--18:10 Anisotropic Inflation

Razieh Emami Meibody (Inst. Res. Fundamental Sciences)

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Thursday, Sept. 13 Cosmic Probes Session 2 UCAS S201 Chair : Eric Linder

14:00--14:20 Strong gravitational lenses as standard rulers in cosmology

Marek Biesiada (U. Silesia)

14:20--14:40 Euclid and the quest for the dark energy

Martin Kunz (Geneva)

14:40--15:00 Impact of weak lensing bispectrum on cosmological parameter

estimation

Masanori Sato (Nagoya U.)

15:00--15:20 Weak lensing generated by vector perturbations and detectability of

cosmic strings

Daisuke Yamauchi (U. Tokyo)

15:20--15:40 Extraction of spectra out of redshift distortion maps

Yong-Seon Song (KASI)

15:40--16:00 Peculiar Velocity Decomposition, Redshift Space Distortion and Velocity

Reconstruction in Redshift Surveys

Yi Zheng (SHAO)


Chair: Valeria Pettorino

16:30--16:50 Testing General Relativity using the Environmental Dependence of Dark

Matter Halos

Gongbo Zhao (NAOC/Portsmouth)

16:50--17:10 The 3D galaxy correlation function and cosmic dust

Wenjuan Fang (UIUC)

17:10--17:30 Galaxy Clusters, non-Gaussianities and Eddington biases

Shaun Hotchkiss (U. Helsinki)

17:30--17:50 Dark radiation and generalized cosmological models

Viviana Niro (U. Barcelona)

17:50--18:10 Gravitational wave signal from massive gravity

Norihiro Tanahashi (UC Davis)

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Plenary Sessions

Monday, Sept. 10 Plenary Session 1 UCAS S201

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Dark Matter & Dark Energy Projects and Progress in China

Yueliang Wu (UCAS/KITPC/ITP)

Inflation & Tests

Leonardo Senatore (Stanford University)

I will discuss recent development in the Theory of Inflation. The theory of the

fluctuations in Inflation can be described in full generality as the theory of a

Goldstone boson that non-linearly realizes the space-time symmetries that are

spontaneously broken by the inflationary solution. This allows us to explore inflation

in a novel very general and essential way. I will discuss what we have really tested of

the theory of Inflation so far after the recent experiments, as well as some recently

found new signatures that we hope to look for in the next CMB and Large Scale

Structure experiments.

Monday, Sept. 10 Plenary Session 1 UCAS S201

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Astrophysical Evidence for Dark Matter

Joel Primack (University of California, Santa Cruz)

ΛCDM has become the standard cosmological model because its predictions agree so

well with observations of the cosmic microwave background and with the large-scale

structure of the universe as shown by comparison of the latest cosmological

simulations with observations. There is strong evidence for dark matter as ΛCDM

predicts in and around clusters from gravitational lensing and X-ray data, and around

galaxies from rotation curve, satellite, and lensing data. However ΛCDM has faced

challenges on sub-galactic scales. Some of these challenges, including the “angular

momentum catastrophe" and the absence of density cusps in the centers of small

galaxies, may be overcome with improvements in simulation resolution and feedback.

Recent simulations appear to form realistic galaxies in agreement with observed

scaling relations. The discovery of many faint galaxies in the Local Group is

consistent with ΛCDM predictions, as is the increasing evidence for substructure in

galaxy dark matter halos from gravitational lensing flux anomalies and gaps in cold

stellar streams. The "too big to fail" (TBTF) problem, which challenges ΛCDM,

arose from analyses of the Aquarius and Via Lactea very high resolution ΛCDM

simulations of dark matter halos like that of the Milky Way. Each simulated halo

had ~10 sub-halos that were so massive and dense that they would appear to be too

big to fail to form lots of stars. The TBTF problem is that none of the observed

satellites of the Milky Way or Andromeda have stars moving as fast as would be

expected in these densest sub-halos. This may indicate the need for a more complex

theory of dark matter -- but the latest simulations suggest that a better understanding

of the interplay of baryonic and dark matter physics may resolve this problem.

Dark Matter Candidates

Paolo Gondolo (University of Utah)

I will give an overview of some of the current particle dark matter candidates: axions,

neutralinos, neutrinos, light WIMPs, 130-GeV WIMPs, and so on.

Tuesday, Sept. 11 Plenary Session 2 UCAS S101

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Recent Results from the Large Hadron Collider

Markus Elsing (CERN)

The recent discovery of a new heavy particle at the Large Hadron Collider (LHC)

with properties compatible with a Higgs boson is a major breakthrough in high energy

physics and opens very exciting prospects for the understanding of electroweak

symmetry breaking. The basis for this success has been the outstanding performance

of the accelerator and of the experiments. In 2012 the LHC has already more than

doubled the integrated luminosity delivered in 2011 to ATLAS, CMS and LHCb, at a

slightly increased centre-of-mass energy of 8 TeV. The data collected in the last two

years is the basis for the very rich physics programme leading to this recent discovery.

Precise measurements at the LHC lead to an improved understanding of Standard

Model QCD and electroweak processes in pp collisions, such as jet, W/Z and top

production, as well as in the area of heavy flavour physics. Searches for

Supersymmetry and for other new physics beyond the Standard Model have not (yet)

shown any positive evidence. New limits on rare B decays and other precision flavour

measurements significantly constrain new physics models that lead to large deviations

from Standard Model predictions. In this talk the latest results from ATLAS, CMS and

LHCb will be reviewed, with a special emphasis on the discovery of the Higgs-like

particle.

Eternal Inflation, and How It Ends

Matthew Kleban (New York University)

I briefly review eternal inflation, where most of the universe is continually

undergoing exponential expansion and our observable universe is contained in a

relatively tiny pocket or bubble. There is both theoretical and observational

motivation for such models, and I explain how they are both potentially falsifiable and

possible to confirm by near-future data. I present a novel model based on the recently

discovered phenomenon of flux discharge cascades, where an eternally inflating

parent phase locally transitions into a "slow roll" inflating phase and then reheats.

This model embeds naturally into string theory and does not require any significant

fine-tuning for consistency with observation. It produces interesting and characteristic

features in the spectrum of perturbations that, if confirmed, would constitute evidence

both for extra dimensions and cosmic bubble collisions.

Tuesday, Sept. 11 Plenary Session 2 UCAS S101

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CMB Science in the Post-WMAP Era

Scott Dodelson (Fermilab/University of Chicago)

In the post-WMAP era, the CMB continues to deliver exciting science results in the

form of confirmation of our basic model. The past year saw the first detection of

CMB lensing by two teams, and projections suggest that this method of probing

structure in the Universe will grow vastly more powerful in the coming years. There

are also tantalizing hints from ground-based experiments for new physics, hints that

will be confirmed or refuted by Planck in the coming year. Where are we now and

what should we look for in the coming years?

Axion or Axino Dark Matter in String Axiverse scenario

Kiwoon Choi (KAIST)

Phenomenologically viable string compactifications generically give rise to many

axions and axinos in low energy effective theory, while their masses and decay

constants depend on some details of moduli stabilization. We discuss a moduli

stabilization scheme involving anomalous U(1) gauge symmetries, and examine the

possibility of an intermediate scale QCD axion as well as the possibility of axino dark

matter.

Wednesday, Sept. 12 Plenary Session 3 UCAS S101

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Dark Energy Research in China

Zuhui Fan (Peking University)

In this presentation, I will talk about the joint efforts that Chinese scientists have

made on dark energy studies, particularly on constraining the properties of dark

energy from cosmological observations. Taking into account dark energy

perturbations for arbitrary equation of state parameters properly, a global fitting

engine was developed from COSMOMC in 2005. Extensive studies have been

subsequently done to derive cosmological constraints on dark energy as well as on

other important parameters from most up-to-date observational data. We have also

carried out significant studies to explore different systematics involved in different

cosmological probes and analyses. I will end by briefly introducing a number of

proposed observational projects that are related to dark energy studies.

Modified Gravity and Cosmology

Pedro Ferreira (University of Oxford)

In the past two decades there has been phenomenal progress in mapping out the large

scale structure of the Universe. Indeed, we are now at a stage where the it may be

possible to test some of the underlying assumptions that go into the currently favoured

cosmological model- lambda CDM. The key assumption is that the Universe is

governed by Einstein's General Theory of Relativity. In my talk I will examine how

current and future observations may be used to test General Relativity. I will discuss

the landscape of models, methods of parameterizing that landscape, and how it may

be probed by current and planned surveys.

Wednesday, Sept. 12 Plenary Session 3 UCAS S101

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Baryo/Leptogenesis

Mikhail Shaposhnikov (EPFL)

I will overview the problem of the matter-antimatter asymmetry of the Universe and

ideas proposed for its solution. Different mechanisms for baryogenesis will be

discussed with special emphasis to those of them that can be experimentally tested.

BBN and New Physics

Kazunori Kohri (KEK)

Big-bang nucleosyntheis (BBN) is a theory to predict light element abundances

produced in the early universe. Compared the theoretical predictions with

observational data, we can check unknown physical phenomena predicted in new

physics models. In particular, BBN is very sensitive to energy injections at cosmic

time t = 0.01 -- 1.E12 sec by decaying or annihilating massive particles. I will discuss

current status of bounds on those massive particles and models which predict those

particles. I will also review the standard big-bang nucleosynthesis for the first 20

minutes of my talk.

Thursday, Sept. 13 Plenary Session 4 UCAS S101

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Inflation and Particle/String Model Building

Nemanja Kaloper (Physics, UC Davis)

Primordial Non-Gaussianity from Inflation

David Wands (University of Portsmouth)

Inflation in the very early universe provides a simple model for the origin of structure

in the universe from initial quantum fluctuations. Fluctuations in a free field have a

Gaussian random distribution, but interactions and non-linearities can give rise to a

non-Gaussian distribution of primordial density perturbations. I will discuss how

different types of non-Gaussianity may be revealed by observations of the cosmic

microwave background anisotropies and/or large-scale structure in galaxy surveys.

Non-Gaussian signatures could identify different classes of inflation the physical

mechanisms by which quantum field fluctuations during inflation are converted into

density perturbations after inflation.

Thursday, Sept. 13 Plenary Session 4 UCAS S101

- 27 -

Large-Scale Structure Observations & Simulations

Yipeng Jing (Shanghai Astronomical Observatory)

I will present some new results on clustering of galaxies from optical and radio

surveys. With numerical simulations, I will explain how to connect galaxies to dark

matter structures, and then present constraints on cosmological models from current

observational data.

Cosmic Accleration Beyond Dark Energy

Albert Stebbins (Fermilab)

I show that even in the context of general relativity that cosmological observations do

not require any form of negative pressure matter, i.e. any dark energy. I then go on

to discuss how plausible alternative interpretations of observations are. It is

plausibility arguments which point to a standard cosmology homogeneous cosmology

with dark energy.

Friday, Sept. 14 Plenary Session 5 UCAS S101

- 28 -

Recent Neutrino Oscillation Results and future

Jun Cao (Institute of High Energy Physics, CAS, Beijing)

It is well established that the flavor of a neutrino oscillates with time. Neutrino

oscillation demonstrates that neutrino has a tiny mass, which is the only observed

phenomenon beyond the standard model of particle physics, and could have

significant impacts on cosmology and astrophysics. Neutrino oscillations can be

described by the three mixing angles ($\theta_{12}$, $\theta_{ 23}$, and

$\theta_{ 13}$) and a phase of the Pontecorvo-Maki-Nakagawa-Sakata matrix, and

two mass-squared differences ( $\Delta m^2_{32}$ and $\Delta m^2_{21}$).

Previous neutrino experiments have measured four of the six parameters. In 2011,

results from T2K, MINOS, and Double Chooz experiments indicated that the last

unknown mixing anlge $\theta_{ 13}$ could be large. Recently, Daya Bay Reactor

Neutrino Experiment observed electron antineutrino disappearance and excuded the

non-zero value of $\theta_{ 13}$ with a significance of 5.2 sigma. Later on theresult

was improved to 7.7sigma. A rate-only analysis finds $\sin^22\theta_{13} = 0.089

\pm 0.010 (stat.) \pm 0.005 (syst.)$ in a 3 neutrino framework. The result was

confirmed by RENO experiment. A large $\theta_{ 13}$ makes it possible to measure

the neutrino mass hierarchy and CP phase in next decade. Several experiments were

proposed in the world to achieve this goal. The neutrino-antineutrino asymmetry

caused by the CP violation may provide hints to why there are much more matter than

antimatter in our universe.

Surveying Dark Energy

Eric Linder (UC Berkeley/LBNL/IEU)

Nearly 15 years after discovery of the acceleration of the universe,where does our

understanding of the physics stand? I discuss some ofthe most recent data and what

we do - and do not - know about dark energy.I discuss recent trends useful for

theorists and observers, and emphasizethat to understand dark energy physics the data

must address not just wbut the dynamics, degrees of freedom, and persistence.

Complementaritybetween surveys is essential and we are in the midst of two data

revolutions:mapping the three-dimensional galaxy distribution and measuring CMB

lensing,both of which greatly improve tests of cosmology and gravity. These

allowgreater progress in the next 5 years than previously thought.

Friday, Sept. 14 Plenary Session 5 UCAS S101

- 29 -

Current and future constraints on neutrinos from large scale

structure

Steen Hannestad (Aarhus University)

Some neutrino properties, such as the absolute mass, can be probed very precisely

using cosmological data. In the talk I will review how neutrinos influence the

formation of structure as well current bounds on neutrino properties, including

hypothetical new sterile neutrinos. I will then discuss future structure formation

probes, mainly the recently approved ESA mission EUCLID and its potential for

probing neutrino physics.

Testing Neutralino Dark Matter

Y-L Sming Tsai (National Centre for Nuclear Research)

Since 2011, we have witnessed significant improvement on theexperimental

sensitivities for detection of cold dark matter byCollaborationslike XENON100 and

Fermi-LAT. Even more importantly, the LHC hasmanaged to push the boundaries for

SUSY discoverybeyond the rosiest predictions, and the Higgs boson seems to have

beendiscovered. In this talk we analyze the impact of this recent experimentalprogress

on Bayesian inferences of SUSY parameter space, and we do soby presenting the

most significant experimental updates inchronological order.Finally, after discussing

the present status of neutralino darkmatter, with also show the constraining power on

parameter space of the projected one-year sensitivities at DeepCore from neutrinos

originating from dark matter annihilation in the Sun.

- 30 -

Public Lecture 7:30 pm, Tuesday, Sept. 11, KITPC 6620

The Dark Side of the Universe

Rocky Kolb (University of Chicago)

Ninety-five percent of the universe is missing! Astronomical observations suggest

that most of the mass of the universe is in a mysterious form called dark matter and

most of the energy in the universe is in an even more mysterious form called dark

energy. Unlocking the secrets of dark matter and dark energy will illuminate the

nature of space and time and connect the quantum with the cosmos.

- 31 -

Parallel Sessions

Monday, Sept. 10 String Cosmology UCAS S204

- 32 -

Parallel Sessions/ String Cosmology

The tachyon unified model: a really universe-like brane Huiquan Li (University of Science and Technology of China)

We find that various problems in the tachyon inflationary model can be (partially)

cured if we set the minimum value of the tachyon potential to be non-zero. Moreover,

an unstable three-brane described by this modified theory is more like our universe

compared with the original tachyon theory: the three-brane can automatically inflate,

(p) reheat, become matter dominated and accelerate in the right time order. Hence,

this provides a unified description of inflation, reheating, dark matter and dark energy.

The universe can be viewed as a three-brane evolving from an unstable state to a

stable state (it is not so in the original theory).

Warped de Sitter solutions in the higher-dimensional gravity Masato Minamitsuji (Yukawa Institute for Theoretical Physics)

We show that the warped de Sitter compactifications are possible under certain

conditions in higher-dimensional gravitational theory coupled to a dilaton, a form

field strength, and a cosmological constant. We find that the solutions of field

equations give de Sitter spacetime with the warped structure, and discuss

cosmological models directly obtained from these solutions. We also construct a

cosmological model in the lower-dimensional effective theory and discuss possible

stabilization mechanism of the extra dimensional space.

Gravitational wave signals of extra dimensions

Ruth Gregory (Durham University)

Cosmic superstrings are generic in brane inflationary models, and may give off

distinct gravitational wave signals from cusps or kinks. I show how motion in internal

dimensions can affect this signal, discussing aspects and caveats of the usual

modelling of strings and the internal dimensions.

Monday, Sept. 10 String Cosmology UCAS S204

- 33 -

Gravitational Waves and Kaluza-Klein Modes from Cosmic Super-Strings Jean-Francois Dufaux (APC, CNRS/Universite Paris 7)

Cosmic super-strings interact generically with Kaluza-Klein modes associated to the

compact internal space. I will discuss the production of Kaluza-Klein modes by

cosmic super-strings and I will show that it is constrained by observations. I will show

that this rules out regions of the parameter space of cosmic super-strings that are

complementary to the regions that can be probed by current and upcoming

gravitational wave experiments.

Correlation between cosmic strings, extra neutrino species and gravity waves Jon Urrestilla (University of the Basque Country, Spain)

The recent observation that the Cosmic Microwave Background (CMB) prefers a

neutrino excess has triggered a number of works studying this possibility. The effect

obtained by the non-interacting massless neutrino excess could be mimicked by some

extra radiation component in the early universe, such as a cosmological gravitational

wave background. It has been noted that a possible candidate to source those

gravitational waves would be cosmic strings. In this talk we explore the possibility of

cosmic strings being the source of the extra radiation component.

Forecast constraints on cosmic string parameters from gravitational wave direct detection experiments Koichi Miyamoto (ICRR, University of Tokyo)

Gravitational waves (GWs) are one of the key signatures of cosmic strings. If GWs

from cosmic strings are detected in future experiments, not only their existence can be

confirmed but also their properties might be probed. In this paper, we study the

determination of cosmic string parameters through direct detection of GW signatures

in future ground-based GW experiments. We consider two types of GWs, bursts and

the stochastic GW background, which provide us with different information about

cosmic string properties. Performing the Fisher matrix calculation on the cosmic

string parameters, such as parameters governing the string tension $G\mu$ and initial

loop size $\alpha$ and the reconnection probability $p$, we find that the two different

types of GW can break degeneracies in some of these parameters and provide better

constraints than those from each measurement.

Monday, Sept. 10 Inflation Session 1 UCAS S204

- 34 -

Parallel Sessions/ Inflation

Higgs Thermal Inflation and the Mu-Term Mark Hindmarsh (University of Sussex)

We consider a class of models of linear F-term hybrid inflation, in which the minimal

supersymmetric standard model (MSSM) is augmented by a singlet inflaton supplying

the Higgs $\mu$-term, and a U(1)$'$ gauge symmetry spontaneously broken at the

end of inflation by a pair of MSSM singlets. This constitutes a minimal

renormalisable extension of the MSSM which has the ingredients for a satisfactory

cosmology, including explanations for inflation, dark matter, neutrino masses and

baryogenesis. Such models can exit inflation to a vacuum characterised by large

Higgs vevs, whose vacuum energy is controlled by supersymmetry-breaking. Given

an unstable large-Higgs vacuum, the true ground state is reached after a period of

thermal inflation at a scale of around $10^9$ GeV, which has important consequences

for the cosmology of the F-term inflation scenario. The scalar spectral index is

reduced to approximately 0.975, and GUT-scale relics are swept away. We investigate

three popular supersymmetry-breaking scenarios, finding the conditions under which

Higgs thermal inflation takes place, and the constraints arising from the requirement

of solving the gravitino problem.

Effective action for the Abelian Higgs model in an expanding universe Marieke Postma (Nikhef)

To confront inflation with observations, in particular the upcoming precision data on

the CMB from the Planck satellite, an accurate theoretical description, including back

reaction effects, is needed. This is a hard problem, because unlike the scattering

calculations usually done in particle physics, inflation is a time-dependent

non-equilibrium process. In this talk I will show how to calculate the one-loop

effective action for an abelian Higgs model. The calculation allows for a FRW

space-time and a time-dependent expectation value for the scalar field. Our result is

manifestly gauge invariant.

Monday, Sept. 10 Inflation Session 1 UCAS S204

- 35 -

Non-Abelian Gauge Field Inflation Azadeh maleknejad (IPM)

Inflationary models are usually based on dynamics of one or more scalar fields

coupled to gravity. In this work we present a new class of inflationary models,

gauge-flation or non-Abelian gauge field inflation, where slow-roll inflation is driven

by a non-Abelian gauge field. This class of models are based on a gauge field theory

with a generic non-Abelian gauge group minimally coupled to gravity. We then focus

on a particular gauge-flation model by specifying the action for the gauge theory

which allows for a successful slow-roll inflation. This model has two parameters the

value of which can be fixed using the CMB and other cosmological data. These

values are within the natural range of parameters in generic grand unified theories of

particle physics.

No-boundary Measure and Preference of Larger E-foldings by Multi-fields Soo A Kim (APCTP)

We study no-boundary wave function of the universe in the context of multi-field

inflation. We will show how to introduce the large number of fields to lift up the

probability to have preference of large e-folding number.

A Geometric Bound on F-term Inflation

Ivonne Zavala (U. Groningen)

I will discuss a geometric bound for the possibility of realising inflation in minimal

supergravity with F-terms. The derivation of the bound crucially depends on the

sGoldstini, the scalar field directions that are singled out by spontaneous

supersymmetry breaking. I will analyse the inflationary implications of this bound,

and in particular discuss to what extent the requirements of single field and slow-roll

can both be met in F-term inflation.

A Cosmological Scenario without Initial Singularity Taotao Qiu (LeCosPA, National Taiwan University)

The inflation scenario suffers from the singularity problem. In order to get rid of the

problem, a kind of "bounce" scenario has been proposed. I'll discuss the condition for

a bounce to happen, and how it can solve other Big-Bang puzzles instead of inflation

so that we may even don't need inflation at all. I analyse the differences between

inflation and bounce in terms of perturbation theory. Concrete bounce model are also

presented as well.

Tuesday, Sept. 11 Inflation Session 2 UCAS S101

- 36 -

Multiple Cosmic Collisions and the CMB Jonathan Kozaczuk (University of California, Santa Cruz)

Models of false vacuum eternal inflation suggest that our observable universe may be

the product of the decay of a false vacuum via "bubble nucleation". If this is the

case, then our own universe will have experienced many collisions with other bubbles

nucleated out of the false vacuum. An observer found to the future of these

collisions may then be able to directly observe the effects of eternal inflation. In this

talk I discuss the general features of "multiple collision scenarios", in which an

observer has many (intersecting) collisions affecting their last scattering surface. In

many cases, one can approximate such scenarios as a superposition of individual

collision events governed by nearly isotropic and angular scale-invariant distributions,

with most bubbles appearing to to take up less than half of the observer's sky. The

resulting signal in the CMB power spectrum is very red-tilted, featuring a dramatic

increase in power in the low multipoles. This prediction is quite model-independent,

and can potentially be used to constrain aspects of eternal inflation and bubble

collision scenarios.

Multiple Inflationary Stages with Varying Equation of State Mohammad Hossein Namjoo (IPM/YITP)

We consider a model of inflation consisting a single fluid with a time-dependent

equation of state. In this phenomenological picture, two periods of inflation are

separated by an intermediate non-inflationary stage which can be either a radiation

dominated, matter dominated or kinetic energy dominated universe, respectively, with

the equation of state $w=1/3$, 0 or 1. We consider the toy model in which the change

in $w$ happens instantaneously. Depending on whether the mode of interest leaves

the horizon before or after or between the phase transitions, the curvature power

spectrum can have non-trivial sinusoidal modulations. This can have interesting

observational implications for CMB anisotropies and for primordial black-hole

formation.


- 37 -

Primordial Black Holes as a Tool for Constraining Non-Gaussianity Christian Byrnes (CERN)

Primordial Black Holes (PBH's) can form in the early Universe from the collapse of

large density fluctuations. Tight observational limits on their abundance constrain the

amplitude of the primordial fluctuations on very small scales which can not otherwise

be constrained, with PBH's only forming from the extremely rare large fluctuations.

The number of PBH's formed is therefore highly sensitive to small changes in the

shape of the tail of the fluctuation distribution, which itself depends on the amount of

non-Gaussianity present. We study how local non-Gaussianity of arbitrary size

(parameterised by fNL and gNL) affects the PBH abundance and the resulting

constraints on the amplitude of the fluctuations on very small scales.

Intriguingly, even non-linearity parameters of order unity have a significant impact on

the PBH abundance. The sign of the non-Gaussianity is particularly important, with

the constraint on the allowed fluctuation amplitude tightening by an order of

magnitude as fNL changes from just -0.5 to 0.5. We show that if PBH's are observed

in the future, then regardless of the amplitude of the fluctuations, non-negligible

negative fNL would be ruled out. Finally we show that gNL may have an even larger

effect on the number of PBH's formed than fNL.

Induced Gravitational Waves from Inflation Laila Alabidi (YITP)

Gravitational waves have been shown to be induced at second order by first order

scalar perturbations during Big Bang Nucleosynthesis. In this talk I will present the

predicted signatures of these induced gravitational waves from given models of

inflation, and show that they will be detectable by proposed space based gravitational

wave detectors, such as DECIGO.

Gravitational Waves Produced by Fermions Tuukka Meriniemi (University of Helsinki)

We compute the spectrum of gravitational waves produced by a fermionic source after

inflation. Several possible gravitational wave production schemes in the early

Universe have been studied before, like bosonic preheating, but this is the first time

when a fermionic source is discussed. Preheating and other particle production

phenomena in the early Universe can give rise to high-energy out-of-equilibrium

fermions. These fermions develop an anisotropic stress which is a source for

gravitational waves. We present a formalism to regularize the source and to calculate

the spectrum of gravitational waves from this process.


- 38 -

Particle Production and Vacuum Selection with Higher Dimensional Operator Seishi Enomoto (Nagoya University)

On the moduli space, there exists a special point where the particle coupled with the

moduli becomes massless, called ESP. It is known that particles interacting with the

moduli are produced when the moduli approaches the ESP, and then the moduli is

trapped around the ESP.

We consider the particle production and the effect of trapping of the moduli with

higher dimensional operator which is suppressed by some cutoff scale. As a result, the

particle production area is larger, and the effect of trapping becomes strong suddenly

when the moduli run away from the ESP when the value of moduli becomes a cutoff

scale.

Metric Perturbation from Inflationary Magnetic Field and Generic Bound on Inflation Models

Teruaki Suyama (The University of Tokyo)

There is an observational indication of extragalactic magnetic fields. No known

astrophysical process can explain the origin of such large scale magnetic fields, which

motivates us to look for their origin in primordial inflation. By solving the linearized

Einstein equations, we study metric perturbations sourced by magnetic fields that are

produced during inflation. This leads to a simple but robust bound on the inflation

models by requiring that the induced metric perturbation should not exceed the

observed value 10^-5. In case of the standard single field inflation model, the bound

can be converted into a lower bound on the Hubble parameter during inflation.

Universal upper limit on inflation scale from cosmic magnetic field Shinji Mukohyama (Kavli IPMU)

Recently observational lower bounds on the strength of cosmic magnetic fields were

reported, based on gamma-ray flux from distant blazars. If inflation is responsible for

the generation of such magnetic fields then the inflation energy scale is bounded from

above as rho_{inf}^{1/4} < 2.5 times 10^{-7} M_{Pl} times (B_{obs} / 10^{-15}

G)^{-2} in a wide class of inflationary magnetogenesis models, where B_{obs} is the

observed strength of cosmic magnetic fields. The tensor-to-scalar ratio is

correspondingly constrained as r < 10^{-19} times (B_{obs}/10^{-15}G)^{-8}.

Therefore, if the reported strength B_{obs} \geq 10^{-15}G is confirmed and if any

signatures of gravitational waves from inflation are detected in the near future, then

our result indicates some tensions between inflationary magnetogenesis and

observations.


- 39 -

Uniqueness of the Gauge Invariant Action for Cosmological Perturbations Jan Weenink (Utrecht University)

The third order action for gauge invariant cosmological perturbations can be called

unique in two aspects. First, it is unique in the sense that the bulk actions for different

gauge invariant variables differ only by terms proportional to the equations of motion,

which do not contribute to the 3-point function. On the other hand, the gauge invariant

action is unique with respect to conformal frames. When expressed in terms of the

comoving curvature perturbation, the action takes a unique form independent of the

original Jordan or Einstein frame. The comoving curvature perturbation is a frame

independent cosmological perturbation, which makes it the variable of choice for

showing the equivalence of frames.

A Backward Formalism for Multi-field Inflation

Lingfei Wang (Lancaster University)

I will explain a general framework based on delta-N formalism to estimate the

cosmological observables pertaining to the cosmic microwave background radiation

for arbitrary potentials and generic end of inflation boundary conditions. This is

achieved by reparameterizing the phase space. I will compare this approach with

related ones and also demonstrate its capabilities through examples whose

perturbations up to bispectra are calculated.

Thursday, Sept. 13 Inflation Session 3 UCAS S101

- 40 -

Higgs Condensation as an Unwanted Curvaton Jun'ichi Yokoyama (RESCEU, University of Tokyo)

Cosmology of the Higgs field in the standard model is discussed in the context of

generalized G inflation model. It is shown that in some cases, the Higgs field plays a

role of a curvaton but it does not create appropriate amplitude and spectrum of

curvature perturbations.

Curvaton Induced Modulated Reheating Osamu Seto (Hokkai-Gakuen University)

We study curvature perturbation in models where a light scalar field does not only

play a role of curvaton but also induce modulated reheating at the inflaton decay. We

calculate the non-linearity parameters as well as the scalar spectral index and the

tensor-to-scalar ratio. We find that there is a parameter region where non-linearity

parameters are also significantly enhanced by the cancellation between the modulated

effect and the curvaton contribution. For the simple quadratic potential model of both

inflaton and curvaton, both tensor-to-scalar ratio and nonlinearity parameters could be

simultaneously large.

Local non-Gaussianity from Rapidly Varying Sound Speeds

Jon Emery (ICG - University of Portsmouth)

Non-Gaussianity is set to play an important role in discriminating between otherwise

degenerate inflationary models. As such, we study the effect of non-trivial sound

speeds on local-type non-Gaussianity during multiple-field inflation. To this end, we

consider a model of multiple-field DBI and use the deltaN formalism to track the

super-horizon evolution of perturbations. We derive analytic expressions for the

relevant quantities in the two-field case, valid beyond slow variation. We find that

non-trivial sound speeds can, in principle, curve the trajectory in such a way that

significant local-type non-Gaussianity is produced. Deviations from slow variation,

such as rapidly varying sound speeds, enhance this effect.


- 41 -

Inhomogenous Non-Gaussianity Gianmassimo Tasinato (ICG, University of Portsmouth)

I discuss a method to probe higher-order correlators of the primordial density field

through the inhomogeneity of local non-Gaussian parameters, such as f_NL,

measured within smaller patches of the sky. The inhomogeneity of non-Gaussian

parameters may be a feasible way to detect or constrain higher-order correlators in

local models of non-Gaussianity, as well as to distinguish between single and

multiple-source scenarios for generating the primordial density perturbation.

Strong scale dependent bispectrum in the Starobinsky model of inflation

Frederico Arroja (Institute for the early universe, Ewha Womans University)

We compute analytically the dominant contribution to the tree-level bispectrum in the

Starobinsky model of inflation. In this model, the potential is vacuum energy

dominated but contains a subdominant linear term which changes the slope abruptly at

a point. We show that on large scales compared with the transition scale $k_0$ and in

the equilateral limit the analogue of the non-linearity parameter scales as $(k/k_0)^2$,

that is its amplitude decays for larger and larger scales until it becomes subdominant

with respect to the usual slow-roll suppressed corrections. On small scales we show

that the non-linearity parameter oscillates with angular frequency given by

$3/k_0$ and its amplitude grows linearly towards smaller scales and can be large

depending on the model parameters. We also compare our results with previous

results in the literature.

Observable non-gaussianity and gravity waves from particle production during inflation Ryo Namba (University of Minnesota)

We present our results for the signatures of particle production in several models of

conventional slow roll inflation:

(1) Observable approximate equilateral non-gaussianity is obtained in models of

natural inflation for the most theoretically motivated values of the axion decay

constant.

(2) Observable approximate local and anisotropic non-gaussianity is obtained from a

dilaton-like coupling between the inflaton and a gauge field (typical of some models

of magnetogenesis).

(3) Observable gravity waves are obtained from the production of relativistic particles

in a sector gravitationally coupled to the inflaton, without spoiling the approximate

scale invariance and gaussianity of the scalar perturbations.


- 42 -

Anomalous High Energy Dependence in Inflationary Density Perturbations

Yi Wang (McGill University)

We study the contribution of spectator massive scalar fields to the inflationary density

perturbations through the universal gravitational coupling. We find that such

contribution has several remarkable properties: it does not decrease as the mass of the

spectator field increases; it has a significant size and cannot be turned off by any

adjustable parameters; and it applies to all massive scalars existed during inflation,

making the overall effect unexpectedly large. As a result, the primordial density

perturbations are anomalously sensitive to the high energy physics.

Influence of heavy modes on perturbations in multiple field inflation Xian Gao (APC, Paris University 7)

We investigate linear cosmological perturbations in multiple field inflationary models

where some of the directions are light while others are heavy (with respect to the

Hubble parameter). By integrating out the massive degrees of freedom, we determine

the multi-dimensional effective theory for the light degrees of freedom and give

explicitly the propagation matrix that replaces the effective sound speed of the

one-dimensional case. We then examine in detail the consequences of a sudden turn

along the inflationary trajectory, in particular the possible breakdown of the low

energy effective theory in case the heavy modes are excited. Resorting to a new basis

in field space, instead of the usual adiabatic/entropic basis, we study the evolution of

the perturbations during the turn. In particular, we compute the power spectrum and

compare with the result obtained from the low energy effective theory.

Investigation of multi-field DBI inflation

Taichi Kidani (ICG, University of Portsmouth)

We investigate multi-field DBI inflation models motivated by string theory. Single

field DBI inflation is disfavoured by observation while multi-field effects have been

shown to alleviate the problem. In this talk, I will present detailed numerical

computations of multi-field effects on observables such as the power spectrum in

multi-field DBI inflation models with hybrid-type potentials and show that

Non-Gaussianities can be used to discriminate between those models.


- 43 -

Stochastic approach to flat and non-flat systems in inflationary universe Tomohiro Takesako (ICRR, University of Tokyo)

We revisited the evolution of flat and non-flat direction system in inflationary

universe using stochastic approach.

We find that the flat-direction eventually evolves as a exactly flat-direction in contrast

to the recent analysis of Enqvist et al (2012). In the analysis, we carefully consider the

contributions from the zero-point fluctuations.

Anisotropic Inflation Razieh Emami Meibody (Institute for Research in Fundamental Sciences)

We revisit the idea of generating primordial anisotropies at the end of inflation in

models of inflation with gauge fields. To be specific we consider the charged hybrid

inflation model where the waterfall field is charged under a U(1) gauge field so the

surface of end of inflation is controlled both by inflaton and the gauge fields. Using N

formalism properly we find that the anisotropies generated at the end of inflation from

the gauge field fluctuations are exponentially suppressed on cosmological scales. This

is because the gauge field evolves exponentially during inflation while in order to

generate appreciable anisotropies at the end of inflation the spectator gauge field has

to be frozen. We argue that this is a generic feature, that is, one can not generate

observable anisotropies at the end of inflation within an FRW background.

Monday, Sept. 10 Dark Matter & Relics Session 1 KITPC6620

- 44 -

Parallel Sessions/Dark Matter& Relics

Dark Matter Results from the XENON100 Experiment Fei Gao (Shanghai Jiao Tong University)

The XENON100 is currently the world leading experiment in search of the Weakly

Interacting Massive Particles (WIMPs) running at the Gran Sasso underground

laboratory in Italy. The dual phase xenon technology allows extremely powerful

background discrimination and precise three dimensional position reconstruction. A

background level of (5.3+-0.6)*10^-3 events/kg/day/ keV is achieved during the

13-month dark matter run in 2011 and 2012. After a blind analysis of the 224.6 live

days data, 2 events were found at a background expectation of 1+-0.2 in the

pre-defined signal region of 6.6 -30.5 keVnr energy range. This result sets the most

stringent limit on spin-independent elastic WIMP-nucleon cross section above 8

GeV/c^2 and fulfilled the designed sensitivity of the XENON100 experiment. In this

talk, the latest results as well as the analysis of dark matter data and calibrations will

be presented.

Strong Evidence for Gamma-ray Line Emission from the Inner Galaxy Meng Su (Harvard/MIT)

Using 3.7 years of \Fermi-LAT data, we examine the diffuse 80-200 GeV emission in

the inner Galaxy and find a resolved gamma-ray feature at $\sim 110-140$ GeV. We

model the spatial distribution of this emission with a $\sim3\degree$ FWHM

Gaussian, finding a best fit position $1.5\degree$ West of the Galactic Center. Even

better fits are obtained for off-center Einasto and power-law profiles, which are

preferred over the null (no line) hypothesis by $6.5 \sigma$ ($5.0 \sigma/5.4

\sigma$ after trials factor correction for one/two line case) assuming an NFW density

profile centered at $(\ell, b)=(-1.5\degree,0\degree)$ with a power index

$\alpha=1.2$ . The energy spectrum of this structure is consistent with a single

spectral line (at energy $127.0\pm 2.0$ GeV with $\chi^2=4.48$ for 4 d.o.f.). A pair

of lines at $110.8\pm 4.4$ GeV and $128.8\pm 2.7$ GeV provides a marginally better

fit (with $\chi^2=1.25$ for 2 d.o.f.). The total luminosity of the structure is

$(3.2\pm0.6)\times 10^{35}$ erg/s, or $(1.7\pm0.4)\times 10^{36}$ photons/sec. The

energies in the two-line case are compatible with a $127.3 \pm 2.7$ GeV WIMP

annihilating through $\gamma \gamma$ and $\gamma Z$ (with $\chi^2=1.67$ for 3

d.o.f.). We describe a possible change to the \Fermi\ scan strategy that would

accumulate S/N on spectral lines in the Galactic center 4 times as fast as the current

survey strategy.


- 45 -

A tentative gamma-ray line from dark matter annihilation at the Fermi Large Area Telescoper Christoph Weniger (MPI Physics, Munchen)

Using 43 months of public gamma-ray data from the Fermi Large Area Telescope, we

find in regions close to the galactic center at energies of 130 GeV a 4.6 sigma excess

that is not inconsistent with a gamma-ray line from dark matter annihilation. When

taking into account the look-elsewhere effect, the significance of the observed

signature is 3.2 sigma. If interpreted in terms of dark matter particles annihilating into

a photon pair, the observations imply a partial annihilation cross-section of about

10^-27 cm^3 s^-1 and a dark matter mass around 130 GeV. We will focus on details

of the statistical analysis and possible caveats, and comment on future prospects.

Remarks on two gamma ray lines from the inner galaxy Ichiro Oda (University of the Ryukyus)

Recently, strong evidence for gamma ray line emission from the inner galaxy has

appeared on the basis of Fermi-LAT data. In our study, we wish to point out that the

two gamma ray lines correspond to WIMPs annihilating to not gamma+Z and

gamma+h but 2 gammas and gamma+Z.

What astrophysics and cosmology tell us about dark matter properties

Oleg Ruchayskiy (CERN)

Current cosmological data are well-described by the LambdaCDM model. Within

this model dark matter is assumed to be non- interacting and to have no primordial

velocities ("cold"). In this talk I will discuss how "cold" the dark matter particles can

really be, what other (non-CDM) dark matter models fit current observational data

and what is known in general about the properties of dark matter particles from

astrophysics and cosmology


- 46 -

Indirect dark matter searches in N-body simulations Emmanuel Nezri (Laboratoire d’Astrophysique de Marseille)

We propose a consistent top-bottom approach for studying the gamma-ray indirect

detection signals and associated backgrounds in cosmological Nbody+hydro

simulation frameworks.

While dark matter (DM) is the key ingredient for a successful theory of structure

formation, its microscopic nature remains elusive. Indirect detection may provide a

powerful test for some strongly motivated DM particle models. Nevertheless,

astrophysical backgrounds are usually expected with amplitudes and spectral features

similar to the chased signals. On galactic scales, these backgrounds arise from

interactions of cosmic rays (CRs) with the interstellar gas, both being difficult to infer

and model in detail from observations. Moreover, the associated predictions

unavoidably come with theoretical errors, which are known to be significant. We

show that a trustworthy guide for such challenging searches can be obtained by

exploiting the full information contained in cosmological simulations of galaxies,

which now include baryonic gas dynamics and star formation. We further insert CR

production and transport from the identified supernova events and fully calculate the

CR distribution in a simulated galaxy. We focus on diffuse gamma-rays, and

self-consistently calculate both the astrophysical galactic emission and the dark matter

signal. We notably show that adiabatic contraction does not necessarily induce large

signal-to-noise ratios in galactic centers, and could anyway be traced from the

astrophysical background itself. We finally discuss how all this may be used as a

generic diagnostic tool for galaxy formation.

Detection of keV scale neutrino dark matter in the universe

Wei Liao (East China University of Science and Technology)

A nice candidate of keV scale warm dark matter is the keV scale sterile neutrino. This

dark matter candidate can be understood in the model with one keV scale

right-handed neutrino and two GeV scale right-handed neutrinos, the $\nu$SM. We

study consequences of this type of dark matter model and in particular we study the

detection of keV scale sterile neutrino dark matter. We show that sterile neutrino dark

matter can be captured by radioactive nuclei. This reaction is of no threshold and the

capture lead to events with mono-energetic electrons. These events are well separated

from the beta decay spectrum of the radioactive nuclei and are easy to discriminate.

This is a new way to detect dark matter in the universe.


- 47 -

Exact Velocity Distributions of Galactic Dark Matter Halos in Gamma-Ray Luminosity Calculations Daniel Hunter (Washington University in St. Louis)

Gamma-ray observation is a possible way to measure the spacial distribution of dark

matter in galactic halos, but some particle models require knowledge of the velocity

distribution to make predictions of the luminosity from self-annihilation. For many

halo models, this cannot be found analytically. Even in cases where it can be derived,

a Maxwell-Boltzmann distribution is often used for the particle velocity in lieu of the

correct distribution. A Maxwell-Boltzmann distribution is only correct, however, for a

singular isothermal sphere. Furthermore, the velocity distribution does not have a

trivial dependence on position, as is usually assumed when calculating line-of-sight

integrals in luminosity formulae. In principle, the interaction rate, sigma*v, must be

included in this integral (commonly called the `J-factor'). We numerically compute the

correct velocity distribution for several halo models and compare luminosity

predictions with those found using a Maxwell-Boltzmann distribution. In many cases,

the Maxwell-Boltzmann distribution is reasonable, but in others, especially when

observing the galactic center, it significantly underestimates the luminosity, implying

that the true constraints on dark matter models may be more strict than previously

thought.

The gradient expansion as a model for non-linear clustering Cornelius Rampf (RWTH Aachen)

We describe the gravitational evolution of cosmological inhomogeneities in a LCDM

universe with a series expansion in powers of Ricci-curvatures. This model can be

thought of a relativistic generalisation of the Zel'dovich approximation. It can be used

for various interests such as calculating non-linear corrections to the matter power

spectrum, cosmological backreaction, to light propagation through a clumpy

spacetime... In this talk, I give an overview of the formalism. Then, I focus on the

perturbative calculation of the matter density contrast. Importantly, this result can be

used far into the non-linear regime by explicit extrapolation, thus into a regime

beyond the capacity of standard perturbation theory at any order. Additionally, I

explicitly compare the fully relativistic solutions with the Newtonian ones and discuss

phenomenological aspects.


- 48 -

The effect of quark interactions on dark matter kinetic decoupling and the smallest dark halos Kenji Kadota (Nagoya University)

The studies of the dark matter kinetic decoupling influencing the size of the smallest

dark matter halos could provide us the powerful cosmological probe on the nature of

the dark matter, in an analogous way that the physics of the decoupling of photons

and baryons have been unveiling the properties of our Universe through the cosmic

microwave background and the baryon acoustic oscillations. In this talk, the dark

matter kinetic decoupling with the emphasis on the DM-quark interactions, in view of

the recent data from the LHC and dark matter direct search experiments, will be

discussed.

Primordial black hole formation from an axion-type curvaton model Naoya Kitajima (University of Tokyo)

We argue that the existence of the cold dark matter is explained by primordial black

holes. We show that a significant number of primordial black holes can be formed in

an axion-llike curvaton model, in which the highly blue-tilted power spectrum of

primordial curvature perturbations is achieved. It is found that the produced black

holes with masses 10^{26}g account for the present cold dark matter. We also argue

the possibility of forming the primordial black holes as seeds of the supermassive

black holes.

On the dissipation of the dark matter Hermano Velten (Bielefeld University / UFES (Brazil) )

Fluids often display dissipative properties. We explore dissipation in the form of bulk

viscosity in the cold dark matter fluid. We constrain this model using current data from

supernovae, baryon acoustic oscillations and the cosmic microwave background. Considering

the isotropic and homogeneous background only, viscous dark matter is allowed to have a

bulk viscosity $\xi_0\sim 10^{7} Pa·s$, also consistent with the expected integrated

Sachs-Wolfe effect (which plagues some models with bulk viscosity). We also investigate the

small-scale formation of viscous dark matter halos. This analysis places significantly stronger

constraints on the dark matter viscosity. The existence of dwarf galaxies is guaranteed only

for very small values of the dark matter viscosity, $\xi_0 \lesssim 10^{-3} Pa·s$.

Tuesday, Sept. 11 Dark Matter & Relics Session 2 KITPC6620

- 49 -

Visible and dark matter from a first-order phase transition in a baryon-symmetric universe Raymond Volkas (The University of Melbourne)

The similar cosmological abundances observed for visible and dark matter suggest a

common origin for both. By viewing the dark matter density as a dark-sector

asymmetry, mirroring the situation in the visible sector, we show that the visible and

dark matter asymmetries may have arisen simultaneously through a first-order phase

transition in the early universe. The dark asymmetry can then be equal and opposite to

the usual visible matter asymmetry, leading to a universe that is symmetric with

respect to a generalised baryon number. We present both a general structure, and a

precisely defined example of a viable model of this type. In that example, the dark

matter is atomic as well as asymmetric, and various cosmological and astrophysical

constraints are derived. Testable consequences for colliders include a Z' boson that

couples through the B-L charge to the visible sector, but also decays invisibly to dark

sector particles. The additional scalar particles in the theory can mix with the standard

Higgs boson and provide other striking signatures. This work was performed with K.

Petraki and M. Trodden.

Affleck-Dine dynamics in gauge-mediated supersymmetry breaking

Kalliopi Petraki (University of Melbourne)

The Affleck-Dine mechanism can efficiently produce asymmetries in low-energy

conserved numbers in supersymmetric models. It may be responsible for both

ordinary baryo/lepto-genesis and/or dark-matter production in a variety of ways.

These include asymmetric dark matter genesis, gravitino dark matter from decays of

Q-balls, or stable dark-matter Q-balls. In this talk I discuss the Affleck-Dine dynamics

in gauge-mediated susy-breaking scenarios with arbitrary messenger scale and

arbitrary scale of baryon-number violation. A large messenger scale, besides being a

possibility, can result in large A terms at low energies, which contribute to the Higgs

mass. I will outline the various parametric regions of Affleck-Dine baryogenesis

corresponding to different cosmological scenarios arising from the formation of

Q-balls and the production of gravitinos.


- 50 -

Neutrinos as the Origin of Dark and Baryonic Matter

Marco Drewes

We demonstrate that three sterile alone neutrinos can simultaneously explain neutrino

oscillations, the observed dark matter and baryon asymmetry of the universe. We

perform the first complete study to identify the range of sterile neutrino properties

consistent with these requirements, combining the study of neutrino abundances and

lepton asymmetries in the early universe with bounds from nucleosynthesis and direct

searches. We find that there is a domain of parameters where all these particles can be

found with present day experimental techniques, using upgrades to existing

experimental facilities. As one of the few testable theories of baryogenesis and dark

matter, this minimal scenario provides an attractive alternative to more common

approaches if the current lack of signals for BSM physics in high energy experiments

and dark matter searches continues.

Left-right symmetric model with a keV-scale dark matter candidate Alexander Kartavtsev (Max Planck Institute for Nuclear Physics)

We analyze leptogenesis in gauge extensions of the Standard Model with keV sterile

neutrino dark matter. We find that in the model it is possible to simultaneously

produce both the observed dark matter abundance and baryon asymmetry of the

Universe. The dark matter abundance is controlled by the entropy produced in the

out of equilibrium decays of a heavy right handed neutrino. The same decays are also

responsible for the production of the baryon asymmetry.

Bose-Einstein Condensate Dark Matter Phase Transition from the Symmetry Breaking of λΦ^4 One-loop Contributions

Abril Suaez (Cinvestav)

One of the alternative candidates to be the nature of Dark Matter is the Scalar Field.

Starting with a Scalar Field on a thermal bath and using the λΦ4 one-loop quantum

correction potential, we rewrite the Klein-Gordon equation in its hydrodynamical

representation and study the phase transition and symmetry breaking of this scalar

field due to temperature variations in the equations of motion. With these results we

might be able to explain some of the paradigms of structure formation for this model.

We also propose that the equations obtained might help to explain at some level the

phase transition of a Bose-Einstein Condensate in terms of a quantum field theory in a

simple way.


- 51 -

Exact Solution to Finite Temperature SFDM: Natural Cores without Feedback

Victor Hugo Robles Sanchez (CINVESTAV IPN)

The SFDM model assumes the dark matter is an scalar field (SF). We take the field to

be in a thermal bath and consider the finite temperature corrections due to the

one-loop contributions. We obtain the evolution equation for the perturbations when

the SF is in the minimum of the potential and find an exact solution for the static

limit.

This solution is a temperature corrected density profile for the early galactic halos that

is intrinsically cored, thus there is no need for large amounts of feedback to solve the

cusp/core problem present in the standard model.

Evolution of magnetic fields, chiral anomalies and lepton asymmetry

Alexey Boyarsky (Leiden University)

It is generally believed that the ground state of the Standard Model at high

temperatures is homogeneous and isotropic. This assumption underlies the

description of many important processes in the early Universe. I will demonstrate that

at non-zero values of baryon and lepton number a translation invariant and

homogeneous state of the plasma becomes unstable and the system transits into a new

state, containing a large-scale magnetic field. The origin of this effect is the parity-

breaking character of weak interactions and chiral anomaly. The influence of chiral

anomaly on the subsequent evolution of the magnetic fields shall also be discussed.

Electroweak Baryogenesis in the MSSM with light neutralinos

Germano Nardini (University Bielefeld)

Electroweak baryogenesis is an attractive scenario for the generation of the baryon

asymmetry of the universe as its realization depends on the presence at the weak scale

of new particles which may be searched for at high energy colliders. In the MSSM it

may only be realized in the presence of light stops. Current bounds on the Higgs mass

demand the heaviest stop to be heavier than several TeV. Moreover the lightest stop

leads to an increase of the gluon-gluon fusion Higgs production cross section which

seems to be in conflict with current LHC data. We show that this tension may be

considerably relaxed in the presence of a lightest neutralino with a mass lower than

around 60~GeV, satisfying all present experimental constraints. The tension can be

also relaxed if the electroweak phase transition occured when the energy density of

the universe was not dominated by radiation.


- 52 -

Non-Equilibrium Field Theory Approach to Leptogenesis

Bjorn Garbrecht (RWTH Aachen)

Baryogenesis via Leptogenesis can be formulated within Non-Equilibrium Field

Theory, when using the Closed-Time-Path Formalism. This serves as a basis in order

to systematically account for finite-density and quantum-coherence effects.

Applications are flavoured Leptogenesis, resonant Leptogenesis and Baryogenesis

from oscillations of light sterile neutrinos. We point out new ways of achieving a

resonant enhancement of the asymmetry without imposing a mass-degeneracy. In

particular, we show that the asymmetry can be induced by the mixing of several Higgs

doublets, that may be found in collider experiments.

Temperature Dependence of Standard Model CP Violation Olli Taanila (Bielefeld University)

We compute the CP-violating part of the bosonic effective action and its temperature

dependence in the Standard Model by integrating out quarks and leptons. We find that

the leading order CP-violating terms occur at order 6 and are all C-odd/P-even.

Furthermore we find the CP-violating operators to be strongly suppressed by

temperature. These results have important implications for baryogenesis, espescially

constraining the temperature in cold electroweak baryogenesis.

Axion production from topological defects

Ken'ichi Saikawa (ICRR, University of Tokyo)

Axion is a good candidate of dark matter of the universe, which arises as a

consequence of the Peccei-Quinn mechanism introduced to solve the strong CP

problem of quantum chromodynamics. The axion models predict the formation of

topological defects such as strings and domain walls, and the evolution of these

defects gives some implications for the early universe cosmology. We investigated the

evolution of topological defects related to the axion models by performing

field-theoretic lattice simulations. We analyzed the spectrum of axions radiated from

the defect networks and found that the axions produced by domain walls give

significant contributions to the relic cold dark matter abundance. We discuss the

constraints to axion models based on the results of numerical simulations.

Monday, Sept. 10 Cosmic Acceleration Session 1 UCAS S201

- 53 -

Parallel Sessions/ Cosmic Acceleration

Error Analysis of Ia Supernova and Query on Cosmic Dark Energy Qiuhe Peng (Nanjing University)

Some serious faults in error analysis of observations for SNIa have been found.

Redoing the same error analysis of SNIa, by our idea, it is found that the average total

observational error of SNIa is obviously greater than 0.55m, so we can't decide

whether the universe is accelerating expansion or not.

Testing General Relativity and LCDM with clusters of galaxies, the CMB and galaxy clustering David Rapetti (DARK, University of Copenhagen)

Combining galaxy cluster data from ROSAT and Chandra, cosmic microwave

background data from WMAP, and galaxy clustering data from WiggleZ, 6dFGS and

BOSS CMASS, we test for consistency the cosmic growth of structure predicted by

General Relativity (GR) and the cosmic expansion history predicted by the

cosmological constant plus cold dark matter paradigm (LCDM). The combination of

these three independent, well studied measurements of the evolution of the mean

energy density and its fluctuations is able to break strong degeneracies between model

parameters. To further tighten constraints on the expansion parameters, we also

include supernova, baryon acoustic oscillation and Cepheid data. We model the key

properties of cosmic growth with the normalization of the matter power spectrum and

the cosmic growth index, and those of cosmic expansion with the mean matter density,

the Hubble constant and a kinematical parameter equivalent to that for the dark energy

equation of state. For a spatially flat geometry and allowing for systematic

uncertainties, we obtain results that are in excellent agreement with GR+LCDM and

represent the tightest and most robust simultaneous constraint on cosmic growth and

expansion to date.

Observational tests of cosmic acceleration

Alireza Hojjati (Simon Fraser University)

Future cosmological surveys will have the ability to measure the growth of large-scale

structure with accuracy sufficient for discriminating between different models of dark

energy and modified gravity. The principal component analysis can be an efficient

way of storing information about the linear growth of structure in a

model-independent way. I describe how one can test different models of large-scale

structure formation using the information stored in the principal components of linear

growth and be used to constrain some modified gravity models.


- 54 -

Chameleon cosmological constraints and degeneracies Daniel Boriero (IFGW – UNICAMP)

Constraints will be presented for the chameleon model taking in account up to date

cosmological data. Along with general results, it is given emphasis in the degeneracy

related to the effective number of relativistic degrees of freedom. Results will also

be presented for the hipothesis that the chameleon model could explain the extra dark

radiation seen in the tail of the cosmic microwave background or that could

accomodate the extra neutrino families hinted by anomalies in neutrino oscillations in

accelerator experiments.

Structure formation in a universe with dark energy clustering

Ole Bjaelde (Aarhus University, Denmark)

The accelerated expansion of the universe is generally attributed to the presence of

dark energy with a strong negative pressure, dominating the gravitational physics on

large scales. The nature of dark energy is, however, still a secret the universe keeps to

itself - at least for now. For this reason, much effort is being invested into testing the

properties of dark energy. One very strong test of the dark energy dynamics is the

formation of structure such as galaxies and especially galaxy clusters. Dark energy's

effect on structure formation can be parameterised using a dark energy equation of

state and a dark energy sound speed. The effect of the equation of state is to change

the expansion rate of the universe, whereas the sound speed specifies spatial

inhomogeneities in the dark energy fluid - i.e. dark energy clustering. In the talk, I

will demonstrate the effect of a dark energy sound speed on structure formation.

Furthermore I will discuss how future cluster surveys can be used effectively to pin

down both the equation of state as well as the sound speed. Finally I will briefly

discuss the possibility of using the distribution of voids in the universe to constrain

dark energy parameters.


- 55 -

Cosmological constraints on the decomposed generalized Chaplygin gas model Yuting Wang (U. of Portsmouth and Dalian U. of Technology)

In this paper we study observational constraints on decomposed Chaplygin gas

cosmologies characterised by a dimensionless parameter $\alpha$, recovering

$\Lambda$CDM in the limit $\alpha=0$. We contrast the barotropic generalized

Chaplygin gas, with a decomposed model of an interacting vacuum energy plus cold

dark matter. The two models share the same background cosmology, but differ in the

evolutions of perturbations. The sound speed of a barotropic fluid is fixed by the

background evolution, whereas in a decomposed model the sound speed of

perturbations is determined by the form of the energy-momentum transfer between

cold dark matter and the vacuum and may deviate from the adiabatic sound speed. In

particular we consider the case where dark matter particles follow geodesics and

perturbations have zero sound speed. We use the current observational data, including

the cosmic microwave background anisotropies, type Ia supernovae, and baryon

acoustic oscillations or large-scale structure. The combined constraints show that only

very small values of $\alpha$, extremely close to the $\Lambda$CDM limit, are

allowed in the barotropic model. By contrast, the geodesic model allows a far wider

range for $\alpha$. In this case, the additional constraint from the Integrated

Sachs-Wolfe data can slightly improve the parameter constraint, but is still too weak

to distinguish the best-fit geodesic model from the $\Lambda$CDM model.

Tuesday, Sept. 11 Cosmic Acceleration Session 2 UCAS S201

- 56 -

Self accelerating universe from non-linear massive gravity

Chunshan Lin (Kavli IPMU)

In this talk, we simply introduce a recently proposed ghost free non-linear massive

gravity theory. By investigating its applications on cosmology, several interesting

cosmological solutions were found. Here I would like to show you two solutions, one

is self-accelerating solution in open FRW background; on the other hand, we study the

fixed points of evolution equations for Bianchi type--I universe, and we found a new

attractor solution with non-vanishing anisotropy, on which the physical metric is

isotropic but the Stuckelberg configuration is anisotropic.

Nonlinear instability of homogeneous and isotropic solutions in massive gravity Emir Gumrukcuoglu (Kavli IPMU, University of Tokyo)

The construction of a finite-range gravity theory has been one of the major challenges

in classical field theory for the last 70 years. Recently, de Rham, Gabadadze and

Tolley constructed a nonlinear theory of massive gravity, which successfully avoids

the complications encountered before. The theory allows for homogeneous and

isotropic solutions with self acceleration, providing an alternative to dark energy.

However, the perturbation analysis shows that at linear level, these solutions contain

only 2 propagating degrees of freedom, as opposed to 5 expected from a massive

spin-2 particle. I will show that at nonlinear order, the extra degrees acquire

non-vanishing kinetic terms. For one of these extra degrees, the sign of the kinetic

term is always negative, leading to a ghost instability in the homogeneous and

isotropic background.

Massive Gravity on de Sitter and Unique Candidate for Partially Massless Gravity

Sébastien Renaux-Petel (Institut Lagrange, Paris)

We derive the decoupling limit of Massive Gravity on de Sitter in an arbitrary number

of space-time dimensions d. By embedding d-dimensional de Sitter into d +

1-dimensional Minkowski, we extract the physical helicity-1 and helicity-0

polarizations of the graviton. The resulting decoupling theory is similar to that

obtained around Minkowski. We take great care at exploring the partially massless

limit and define the unique fully non-linear candidate theory that is free of the

helicity-0 mode in the decoupling limit, and which therefore propagates only four

degrees of freedom in four dimensions. In the latter situation, a new Vainshtein

mechanism is at work in the limit m^2 \to H^2, which implies that the usual bounds

on the graviton mass could equivalently well be interpreted as bounds on m^2-2 H^2.


- 57 -

Non-linear structure formation in a gradient expansion Wessel Valkenburg (Leiden University)

I describe inhomogeneities in a LambdaCDM universe with a gradient series

expansion and show that it describes the gravitational evolution far into the non-linear

regime and beyond the capacity of standard perturbation theory at any order.

Vainshtein screening in a cosmological background in the most general second-order scalar-tensor theory

Rampei Kimura (Hiroshima University)

A generic second-order scalar-tensor theory contains a nonlinear derivative

self-interaction of the scalar degree of freedom phi a la Galileon models, which allows

for the Vainshtein screening mechanism. We will discuss this effect on subhorizon

scales in a cosmological background, based on the most general second-order

scalar-tensor theory. Our analysis takes into account all the relevant nonlinear terms

and the effect of metric perturbations consistently. We derive an explicit form of

Newton constant, which in general is time-dependent and hence is constrained from

observations, as suggested earlier. We will also show that in the most general case the

inverse-square law cannot be reproduced on the smallest scales.

f(R) gravity and eV-mass sterile neutrinos Hayato Motohashi (RESCEU, University of Tokyo)

f(R) gravity is a simple and nontrivial extension of General Relativity which has

recently received much attention to explain the present accelerated expansion of the

Universe without cosmological constant. It changes the effective gravitational

constant, and enhances the evolution of matter density fluctuations. Since this

enhancement cancels the suppression by free streaming of massive neutrinos, the

allowed range of neutrino mass is relaxed in f(R) gravity. We applied this mechanism

to sterile neutrinos and showed that the tension between recent neutrino oscillation

experiments, favoring sterile neutrinos with mass of order of 1 eV, and cosmological

data which impose stringent constraints on neutrino masses from the free streaming

suppression of density fluctuations, can be resolved in f(R) gravity.


- 58 -

Nonlinear Perturbations in a Nonsingular Bounce BingKan Xue (Princeton University)

In bouncing cosmologies, nearly scale invariant curvature perturbations are generated

in a contraction phase before a bounce into the standard expansion phase. In a

nonsingular bounce the universe reverses from contraction to expansion at a finite size

and low energy density, which can be effectively described by classical evolutions of

scalar fields coupled to general relativity. The challenge is whether the scale

invariance of the power spectrum is preserved through the nonsingular bounce during

which the perturbations become strongly coupled. Here we present the first complete

numerical simulation of a nonsingular bounce. We study the nonlinear evolution of

curvature perturbations and examine possible changes of the power spectrum across

the nonsingular bounce.

Natural Dark Energy from Lorentz Breaking

Blas Diego (CERN)

I will present a model where the expansion of the universe is driven by a term

insensitive to big quantum corrections. This model naturally occurs in theories of

gravity with Lorentz Breaking. Besides, it has the nice property of possessing a

known UV completion. Finally, I'll discuss the growth of cosmological perturbations,

which allows to distinguish this model from LCDM.

Cleaning up the cosmological constant Antonio Padilla (University of Nottingham)

We present a novel idea for screening the vacuum energy contribution to the overall

value of the cosmological constant, thereby enabling us to choose the bare value of

the vacuum curvature empirically, without any need to worry about the zero-point

energy contributions of each particle. The trick is to couple matter to a metric that is

really a composite of other fields, with the property that the square-root of its

determinant is the integrand of a topological invariant, and/or a total derivative. This

ensures that the vacuum energy contribution to the Lagrangian is non-dynamical. We

then give an explicit example of a theory with this property that is free from

Ostrogradski ghosts, and is consistent with solar system physics and cosmological

tests.


- 59 -

Disformally coupled quintessence

Tomi Koivisto (ITA, Oslo)

Scalar fields from fundamental theories are expected to mediate fifth forces, but such

are stringently constrained by local experiments. However, by considering a disformal

matter coupling, the fifth force can be naturally screened. This new screening

mechanism is explained in the talk, and the implications to the large-scale structure

and constraints on dark energy models based on a disformal coupling are presented.

Cosmological pertrubations in k-essence model revised

Jiro Matsumoto (Nagoya U.)

Subhorizon approximation is often used in cosmological perturbation theory. In this

paper, however, it is shown that the subhorizon approximation is not always a good

approximation at least in case of $k$-essence model. We also show that the sound

speed given by $k$-essence model exerts a huge influence on the time evolution of

the matter density perturbation, and the future observations could clarify the

differences between the $\Lambda$CDM model and $k$-essence model.

Monday, Sept. 10 Cosmic Probes Session 1 UCAS S201

- 60 -

Parallel Sessions/ Cosmic Probes

21cm intensity mapping as a probe of cosmology Xuelei Chen (National Astronomical Observatories of China)

With relatively low cost, the large scale structure can be mapped out with low angular

resolution 21cm observation without attempting to observe individual galaxies,

making it an attractive technique for cosmological studies. I will introduce the basic

principle of 21cm intensity mapping, and describe the Tianlai project, a Chinese

project for such observation.

Intensity Mapping of the [CII] Fine Structure Line during the Epoch of Reionization Yan Gong (University of California, Irvine)

The atomic CII fine-structure line is one of the brightest lines in a typical star-forming

galaxy spectrum with a luminosity ~ 0.1% to 1% of the bolometric luminosity. It is

potentially a reliable tracer of the dense gas distribution at high redshifts and could

provide an additional probe to the era of reionization. By taking into account of the

spontaneous, stimulated and collisional emission of the CII line, we calculate the spin

temperature and the mean intensity as a function of the redshift. When averaged over

a cosmologically large volume, we find that the CII emission from ionized carbon in

individual galaxies is larger than the signal generated by carbon in the intergalactic

medium (IGM). Assuming that the CII luminosity is proportional to the carbon mass

in dark matter halos, we also compute the power spectrum of the CII line intensity at

various redshifts. In order to avoid the contamination from CO rotational lines at low

redshift when targeting a CII survey at high redshifts, we propose the

cross-correlation of CII and 21-cm line emission from high redshifts. To explore the

detectability of the CII signal from reionization, we also evaluate the expected errors

on the CII power spectrum and CII-21 cm cross power spectrum based on the design

of the future milimeter surveys. We note that the CII-21 cm cross power spectrum

contains interesting features that captures physics during reionization, including the

ionized bubble sizes and the mean ionization fraction, which are challenging to

measure from 21-cm data alone. We propose an instrumental concept for the

reionization CII experiment targeting the frequency range of ~ 200 to 300 GHz with 1,

3 and 10 meter apertures and a bolometric spectrometer array with 64 independent

spectral pixels with about 20,000 bolometers.


- 61 -

21cm radiation from minihalos as a probe of small primordial non-Gaussianity Siri Chongchitnan (Abertay Dundee University)

In this talk I shall present a new probe of primordial non-Gaussianity using the 21cm

radiation from minihalos at high redshifts. I consider the fluctuations in the brightness

temperature (measured against the cosmic microwave background) of the 21cm

background from minihalos containing HI, and find a significant enhancement due to

small non-Gaussianity with amplitude f_NL=O(1). This enhancement can be

attributed to the nonlinear bias which is increased in the presence of non-Gaussianity.

I show that these results are robust against changes in the assumed mass function and

some physical aspects of minihalo formation, but are nevertheless sensitive to the

presence of strong radiation sources within or around the minihalos. These results are

relevant for constraining and searching for small primordial non-Gaussianity with

upcoming radio telescopes such as LOFAR and SKA.

Probing dark interactions Valeria Pettorino (University of Geneva)

I will review cosmologies in which there is an interaction in the dark sector: dark

matter - dark energy; dark energy - neutrinos; non minimal coupling to gravity. I will

illustrate how we constrain such models using CMB and large scale structures, both

using present data and forecasts for future surveys.


- 62 -

Neutrino properties from future galaxy surveys

Jan Hamann (Aarhus University)

We discuss how measurements of cosmic shear and galaxy power spectra by future

large-volume galaxy redshift surveys, such as ESA's Euclid mission, will be able to

constrain neutrino properties.

Thursday, Sept. 13 Cosmic Probes Session 2 UCAS S201

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Strong gravitational lenses as standard rulers in cosmology

Marek Biesiada (University of Silesia, Katowice,Poland)

The accelerating expansion of the Universe is a great challenge for both physics and

cosmology. Its discovery was possible because of the advances in the extragalactic

distance measurements. While standard candles most notably Type Ia supernovae

kicked off the issue, it is clear that statistical standard rulers like the Baryon Acoustic

Oscillations are playing an increasingly important role. I will show that strongly

gravitationally lensed systems with known central velocity dispersion of the lens, are

good candidates for a new class of individual standard rulers - Einstein radius being

standardized by stellar kinematics. This approach, pursued recently by us, is

becoming attractive in light of ongoing lens surveys like SLACS or BELLS based on

different protocols than older searches.

Euclid and the quest for the dark energy Martin Kunz (University of Geneva)

Euclid:

Euclid is an ESA medium class mission selected for launch in 2019 in the Cosmic

Vision 2015- 2025 programme. The main goal of Euclid is to understand the origin of

the accelerating expansion of the Universe, but it will address a wide range of science

questions. In my presentation I will give an overview of the cosmological science

goals of Euclid, with a special emphasis on constraints on the properties of the dark

energy and tests of modified gravity.

BEAMS:

Future surveys such as the Dark Energy Survey and the Large Synoptic Survey

Telescope will produce an unprecedented amount of photometric supernova data, not

all of which can be followed up spectroscopically. However, reliable identification of

supernova types requires spectroscopic information, and a contamination with non-Ia

supernova can significantly bias cosmological results. BEAMS (Bayesian Estimation

Applied to Multiple Species) is a fully Bayesian analysis technique designed to take

such contamination into account from the start and to produce unbiased parameter

estimates. In my talk, I will explain how BEAMS works and how it is applied to

supernova cosmology, based on the SDSS supernova sample.


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Impact of weak lensing bispectrum on cosmological parameter estimation Masanori Sato (Nagoya University)

From the cosmic microwave observation, we know the density fluctuations in the

primordial universe follow almost Gaussian distribution. Therefore the power

spectrum analysis gives us the almost all of the cosmological information in the

primordial universe. However, the large scale structures of the present universe have

higher order correlations such as the bispectrum due to the nonlinear growth of the

matters. Therefore, it is important to examine how the cosmological information

contained in the bispectrum affects cosmological parameter estimations.

We use 1000 weak-lensing ray-tracing simulations performed by Seo et al. 2012 (ApJ,

748, 57). We obtain covariance matrix of power spectrum and bispectrum from 1000

realizations, and perform the Fisher matrix analysis to constrain the cosmological

parameters using power spectrum and bispectrum. In this presentation, we show how

the bispectrum improve the constraints of cosmological parameters. We discuss the

effect of the cross covariance of power spectrum and bispectrum.

Weak lensing generated by vector perturbations and detectability of cosmic strings Daisuke Yamauchi (ICRR, University of Tokyo)

We study the observational signature of vector metric perturbations through the effect

of weak gravitational lensing. In the presence of vector perturbations, the

non-vanishing signals for B-mode cosmic shear and curl-mode deflection angle,

which have never appeared in the case of scalar metric perturbations, naturally arise.

Solving the geodesic and geodesic deviation equations, we drive the full-sky formulas

for angular power spectra of weak lensing signals, and give the explicit expressions

for E-/B-mode cosmic shear and gradient-/curl-mode deflection angle. As a possible

source for seeding vector perturbations, we then consider a cosmic string network,

and discuss its detectability from upcoming weak lensing and CMB measurements.

Based on the formulas and a simple model for cosmic string network, we calculate the

angular power spectra and expected signal-to-noise ratios for the B-mode cosmic

shear and curl-mode deflection angle. We find that the weak lensing signals are

enhanced for a smaller intercommuting probability of the string network, $P$, and

they are potentially detectable from the upcoming cosmic shear and CMB lensing

observations. For $P\sim 10^{-1}$, the minimum detectable tension of the cosmic

string will be down to $G\mu\sim 5\times 10^{-8}$. With a theoretically inferred

smallest value $P\sim 10^{-3}$, we could even detect the string with $G\mu\sim

5\times 10^{-10}$.


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Extraction of spectra out of redshift distortion maps

Yong-Seon Song (Korea Astronomy and Space Science Institute)

We introduce the way to decompose spectra and distance measures out of redshift

surveys. The observed spectra of galaxies are distorted by the motion along the line of

sight, which include most precious information of our universe, density-density

spectra, coherent motions, and distance measures. Those components are able to be

measured simultaneously.

Peculiar Velocity Decomposition, Redshift Space Distortion and Velocity Reconstruction in Redshift Surveys Yi Zheng (SHAO)

We propose a mathematically unique and physically motivated decomposition of

peculiar velocity into three eigen-components: an irrotational component completely

correlated with the underlying density field (${\bf v}_\delta$), an irrotational

component uncorrelated with the density field (${\bf v}_S$) and a rotational (curl)

component (${\bf v}_B$). This decomposition has the potential to simplify and

improve the RSD modeling. Specially, we identify a significant systematical error

causing underestimation of the structure growth parameter $f$ by as much as

$O(10\%)$ even at relatively large scale $k=0.1h/$Mpc described by a window

function $W(k)=P_{\delta\theta}/P_{\delta\delta}$. We derive a new formula for the

redshift space power spectrum. Using high resolution simulations, we study the

statistical properties of 3 velocity modes and verify some assumptions utilized in our

RSD fomula. Specially we find a simple fitting function of $W(k) =1/(1+\alpha

f^\beta \Delta^2 _{\delta \delta}) $ with only 2 free parameters. This function is

accurate within $5\%$ at scales corresponding to $\Delta^2_{\delta\delta}<4(10)$ at

$z=1(0)$. Using velocity decomposition, we also discuss 2 possible ways to fulfil the

3D ${\bf v}_\delta$ reconstruction. Both use the otherwise troublesome RSD in

velocity reconstruction as a valuable source of information and can automatically and

significantly alleviate the galaxy bias problem.

Testing General Relativity using the Environmental Dependence of Dark Matter Halos Gongbo Zhao (NAOC/Portsmouth)

I will focus on the investigation of the environmental dependence of dark matter halos

in theories that attempt to explain the accelerated expansion of the Universe by

modifying general relativity (GR). Using high-resolution N-body simulations in f(R)

gravity models which recover GR in dense environments by virtue of the chameleon

mechanism, we find a strong environmentally-dependent difference between the

lensing mass and dynamical mass estimates of dark matter halos. This environmental

dependence of the halo properties can be used as a smoking gun to test GR

observationally.


- 66 -

The 3D galaxy correlation function and cosmic dust Wenjuan Fang (University of Illinois at Urbana Champaign)

Similar to the magnification of galaxies' fluxes by gravitational lensing, the extinction

of the fluxes by comic dust, whose existence is recently detected by Menard et al

(2009), also modify the distribution of a flux-selected galaxy sample. We study the

anisotropic distortion by dust extinction to the 3D galaxy correlation function,

including magnification bias and redshift distortion at the same time. We find the

extinction distortion is most significant along the line of sight and at large separations,

similar to that by magnification bias. The correction from dust extinction is negative

except at sufficiently large transverse separations, which is almost always opposite to

that from magnification bias (we consider a number count slope s > 0.4). Hence, the

distortions from these two effects tend to reduce each other. At low z (~<1), the

distortion by extinction is stronger than that by magnification bias, but at high z, the

reverse holds. We also study how dust extinction affects probes in real space of the

baryon acoustic oscillations (BAO) and the linear redshift distortion parameter beta.

We find its effect on BAO is negligible. However, it introduces a positive

scale-dependent correction to beta that can be as large as a few percent. At the same

time, we also find a negative scale-dependent correction from magnification bias,

which is up to percent level at low z, but to ~40% at high z. These corrections are

non-negligible for precision cosmology, and should be considered when testing

General Relativity through the scale-dependence of beta.

Galaxy Clusters, non-Gaussianities and Eddington biases

Shaun Hotchkiss (University of Helsinki)

The abundance of extreme galaxy clusters is a sensitive probe of primordial

non-Gaussianity. I will review the state of this field, as well as discussing a few

statistical issues that makes the analysis of the abundance of extreme clusters a

delicate issue.


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Dark radiation and generalized cosmological models Viviana Niro (U. Barcelona)

We present a global analysis of cosmological observables in models with additional

relativistic degrees of freedom and non-standard dark matter scenarios. We employ

cosmic microwave background datasets, measurements of the present day Hubble

constant, type-Ia supernovae data and the information on the Baryon Acoustic

Oscillation scale. Using these experimental results, we estimate the cosmological

parameters within such generalized models and we compare our findings with the

ones from $\Lambda$CDM models.

Gravitational wave signal from massive gravity Norihiro Tanahashi (UC Davis)

We discuss the detectability of the mass of gravitational waves, which typically

appears in massive gravity theories, by means of the stochastic gravitational wave

observations. We conduct the analysis based on a general quadratic action, and thus

the results apply universally to any specific massive gravity theories in which the

modifications from general relativity appears in the tensor modes. Notable features of

the results are that we expect a sharp peak to appear in the gravitational wave

spectrum, and that the peak position and height may tell us the graviton mass of today

and the length of the inflationary period. We also discuss the detectability of such a

gravitational wave signal using the future-planned gravitational wave observatories.

Tuesday, Sept. 11 CMB Session KITPC6420

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Parallel Sessions/Cosmic Microwave Background

Second Order Perturbations of the CMB Christian Fidler (ICG Portsmouth)

We study second order perturbations of the CMB. These perturbations are important

as background to observationally interesting quantities like B-polarization and

primordial nongaussianity of the CMB. With increasing precision of future

experiments it is necessary to understand the amount of nongaussianity and

B-polarization induced form second order dynamics. To solve this problem we

develop a numerical code which computes the full second order polarized CMB

spectra and bispectra.

Second order Boltzman code and CMB Bispectrum Zhiqi Huang (IPhT, CEA/Saclay)

I will talk about a second-order Boltzmann code and how its accuracy is numerically

checked using the energy- and momentum- constraint equations at second order and

the squeezed-limit analytical solutions. The contamination to the CMB bispectrum

due to nonlinear GR effect will be discussed.

Planck Era Black Hole Remnants and CMB Quadrupole Anomaly Pisin Chen (National Taiwan University)

It is known that there exists a persistent discrepancy between the observed lower

modes of the CMB spectrum and the Lambda-CDM model, the so-called CMB

quadrupole anomaly. We propose that this quadrupole anomaly could be the imprint

of the remnants of the primordial black holes spontaneously generated during the

Planck era. Copious primordial black holes (PBH) at around the Planck mass and size

can be generated during the Planck era as a result of space-time fluctuations. Such

PBHs would soon be evaporated due to Hawking radiation and the primordial

universe would return to hot radiation prior to the onset of inflation. However

according to the generalized uncertainty principle (GUP), the PBH would not

evaporate entirely but leave behind a remnant (BHR) at Planck mass and size. We

show that if so, then the universe would evolve into a brief moment of

matter-dominance consisted of BHRs before the inflation begins. We further show

that such a BHR matter-dominant universe would induce a suppression of fluctuations

at the initial stage of inflation. By comparison with the latest observational data from

the WMAP collaboration, we find that our model is able to explain the quadrupole

anomaly of the CMB power spectrum.

Tuesday, Sept. 11 CMB Session KITPC6420

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Exploring the origin of the fine structures in the CMB temperature angular power spectrum Kohei Kumazaki (Nagoya U.)

The angular power spectrum of the cosmic microwave background (CMB)

temperature anisotropies is a good probe to look into the primordial density

fluctuations at the largest scales in the universe. Here we re-examine the angular

power spectrum of the Wilkinson Microwave Anisotropy Probe data, paying

particular attention to the fine structures (oscillations) at $\ell=100 \sim 150$ reported

by several authors.Using Monte-Carlo simulations, we confirm that the gap from the

simple power law spectrum is a rare event, about 2.5--3$\sigma$, if these fine

structures are generated by experimental noise and the cosmic variance. Next, in order

to identify the origin of the structures, we investigate frequency and direction

dependencies of the fine structure by dividing the observed QUV maps into four sky

regions. Although the angular power spectra do not have significant dependency on

the frequency and direction in whole, it is found that the power spectrum in the South

East region alone shows a deviation from the distribution of our Monte Calro

simulations above $3 \sigma$. The structure seems to have both contributions from

the fourground and cosmology.

Parity violation of gravitons in the CMB bispectrum

Maresuke Shiraishi (Nagoya U.)

We investigate the cosmic microwave background (CMB) bispectra of the intensity

(temperature) and polarization modes induced by the graviton non-Gaussianities,

which arise from the parity-conserving and parity-violating Weyl cubic terms with

time-dependent coupling. By considering the time-dependent coupling, we find that

even in the exact de Sitter space time, the parity violation still appears in the

three-point function of the primordial gravitational waves and could become large.

Through the estimation of the CMB bispectra, we demonstrate that the signals

generated from the parity-conserving and parity-violating terms appear in completely

different configurations of multipoles. For example, the parity-conserving

non-Gaussianity induces the nonzero CMB temperature bispectrum in the

configuration with $\sum_{n=1}^3\ell_n={\rm even}$ and, while due to the parity-

violating non-Gaussianity, the CMB temperature bispectrum also appears for $\sum_

{n=1}^3\ell_n={\rm odd}$. This signal is just good evidence of the parity violation in

the non-Gaussianity of primordial gravitational waves. We find that the shape of this

non-Gaussianity is similar to the so-called equilateral one and the amplitudes of these

spectra at large scale are roughly estimated as $|b_{\ell \ell \ell}| \sim \ell^{-4} \times

3.2 \times 10^{-2} \left( {\rm GeV} / \Lambda \right)^2 \left(r / 0.1\right)^4$, where

$\Lambda$ is an energy scale that sets the magnitude of the Weyl cubic terms (higher

derivative corrections) and $r$ is a tensor-to-scalar ratio. Taking the limit for the

nonlinearity parameter of the equilateral type as $f_{\rm NL}^{\rm eq} < 300$, we

can obtain a bound as $\Lambda\gtrsim3 \times 10^6 {\rm GeV}$, assuming $r=0.1$.

- 70 -

List of Participants

Firstname Lastname Affiliation

Laila Alabidi YITP

Zhen-Dong An Shanghai Institute of Applied Physics,CAS

Xi-Chen Ao Shanghai Normal University

Frederico Arroja Institute for the early universe, Ewha Womans Univ

Anastasios Avgoustidis University of Nottingham

Dong Bai Graduate University of CAS

Tobias Basse Aarhus University

Xiao-Jun Bi IHEP, CAS

Marek Biesiada University of Silesia, Katowice,Poland

Ole Bjaelde Aarhus University, Denmark

Daniel Boriero IFGW - UNICAMP

Neda Bostani IHEP

Alexey Boyarsky Leiden University

Christian Byrnes CERN

Rong-Gen Cai Institute of Theoretical Physics, CAS

Liang Cao NAOC

Jun Cao Institute of High Energy Physics

Ning Chen Tsinghua University

Xue-Lei Chen NAOC

Song Chen Bielefeld University

Tai-Jun Chen DAMTP, University of Cambridge

Nan Chen Department of Physics,Tsinghua University

Shao-Long Chen Central China Normal University

Pisin Chen National Taiwan University

Jing Chen ITP

Cheng Cheng ITP

- 71 -


Kiwoon Choi KAIST

Siri Chongchitnan Abertay Dundee University

Guido D 'Amico New York University

Blas Diego CERN

Scott Dodeslon Fermilab/University of Chicago

Marco Drewes Technische Universität München

Jean-Francois Dufaux APC, CNRS/Universite Paris 7

Markus Elsing CERN

Razieh Emami Meibody Institute for Research in Fundamental Sciences

Jon Emery ICG - University of Portsmouth

Seishi Enomoto Nagoya University

Jarah Evslin IHEP, CAS

Zu-Hui Fan Peking University

Wen-Juan Fang University of Illinois at Urbana Champaign

Kai-xi Feng University of Chinese Academy of Sciences

Pedro Ferreira University of Oxford

Christian Fidler ICG Portsmouth

Liang Gao NAOC

Chang-Jun Gao National Astronomical Observatories

Xian Gao APC, Paris University 7

Fei Gao Shanghai Jiao Tong University

Peng-Yuan Gao National Astronomical Observatories of China

Bjorn Garbrecht RWTH Aachen

Luis Garcia UERJ

Paolo Gondolo University of Utah

Yan Gong University of California, Irvine

Yun-Gui Gong Huazhong University of Science and Technology

Ruth Gregory Durham University

Emir Gumrukcuoglu Kavli IPMU, University of Tokyo

Zong-Kuan Guo ITP, CAS

- 72 -


Jan Hamann Aarhus University

Miao Han Shanghai Astronomical Observatory

Steen Hannestad Aarhus University

Rasmus Sloth Hansen Aarhus University

Mark Hindmarsh University of Sussex

Alireza Hojjati Simon Fraser University

Shaun Hotchkiss University of Helsinki

Yang Hu Peking Univ.

Qing-Guo Huang Institute of theoretical physics, CAS

Zhi-Qi Huang IPhT, CEA/Saclay

Xiao-Yuan Huang IHEP

Wei-Cong Huang ITP

Xiao-Yuan Huang NAOC

Qi-Zhi Huang NAOC

Daniel Hunter Washington University in St. Louis

Dong Ji University of Chinese Academy of Sciences

Yi-Peng Jing Shanghai Astronomical Observatory

Alexander Jost RWTH Aachen

Philippe Journeau Discinnet Labs

Kenji Kadota Nagoya University

Nemanja Kaloper Physics, UC Davis

Alexander Kartavtsev Max Planck Institute for Nuclear Physics

Shahram Khosravi School of Astronomy,IPM

Taichi Kidani ICG, University of Portsmouth

Soo A Kim APCTP

Rampei Kimura Hiroshima University

Naoya Kitajima University of Tokyo

Matthew Kleban New York University

Kazunori Kohri KEK

Tomi Koivisto ITA, Oslo

- 73 -


Edward Kolb University of Chicago

Jonathan Kozaczuk University of California, Santa Cruz

Kohei Kumazaki Nagoya University

Martin Kunz University of Geneva

Piret Kuusk Institute of Physics, University of Tartu, Estonia

Mikhail Kuznetsov MIPT & INR RAS, Moscow

Cui-Ling Lan Center for International Scientific Exchanges, CAS

Jia-Lin Li shanghai normal university

Ming-Zhe Li Department of Physics, Nanjing University

Chang-Hong Li Nanjing University

Hong Li Institute of high energy physics

Hui-Quan Li University of Science and Technology of China

Miao Li ITP

Tai Li ITP

Zhi-Gang Li NAOC

Yi-Chao Li NAOC

Wei Liao East China University of Science and Technology

Lei Liao Graduate student of Guangzhou University

Tong-Yan Lin Harvard University / KICP

Chun-Shan Lin Kavli IPMU

Su-Jie Lin IHEP

Eric Linder UC Berkeley/LBNL/IEU

Jie Liu University of Chinese Academy of Sciences

Zhi-Guo Liu University of Chinese Academy of Sciences

Da Liu ITP

Wei Liu NAOC

Lei Ma Fudan University

Qing-Bo Ma Purple Mountain Observatory

Azadeh Maleknejad IPM

Manzoor Malik University of Kashmir

- 74 -


Circella Marco INFN Bari

Jiro Matsumoto Nagoya University

Xiao-Lei Meng BNU/NAOC

Xin-He Meng Nankai U

Jun Meng ITP

Zeeya Merali Foundational Questions Institute

Tuukka Meriniemi University of Helsinki

Yan-Gang Miao Nankai University

Sen Miao ITP

Masato Minamitsuji Yukawa Institute for Theoretical Physics

Taghi Mirtorabi School of Astronomy, IPM

Koichi Miyamoto ICRR, University of Tokyo

Hayato Motohashi RESCEU, University of Tokyo

Shinji Mukohyama IPMU, University of Tokyo

Ryo Namba University of Minnesota

MohammadHossein Namjoo IPM , YITP

Germano Nardini Universität Bielefeld

Emmanuel Nezri LAM

Kai-Xuan Ni Shanghai Jiao Tong University

Viviana Niro University of Barcelona, Spain

Ichiro Oda University of the Ryukyus

Antonio Padilla University of Nottingham

Qiu-He Peng Nanjing University

Kalliopi Petraki University of Melbourne

Valeria Pettorino University of Geneva

Yun-Song Piao Graduated Univercity of CAS

Marieke Postma Nikhef

Joel Primack University of California, Santa Cruz

Cong-Feng Qiao University of Chinese Academy of Sciences

Shi Qi Purple Mountain Observatory, CAS

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Tao-Tao Qiu LeCosPA, National Taiwan University

Cornelius Rampf RWTH Aachen

David Rapetti DARK, University of Copenhagen

Sébastien Renaux-Petel Institut Lagrange, Paris

Victor Hugo Robles Sanchez CINVESTAV IPN

Matts Roos Dept. of Physics,Univ.of Helsinki

Leszek Roszkowski NCBJ, Warsaw/Sheffield

Oleg Ruchayskiy CERN

Ken'ichi Saikawa ICRR, University of Tokyo

Emmanuel Saridakis Baylor U.

Srdjan Sarikas Max Planck Institute for Physics, Munich

Masanori Sato Nagoya University

Christian Schultz Aarhus University

Leonardo Senatore Stanford University

Osamu Seto Hokkai-Gakuen University

Chung-Lin Shan Institute of Physics, Academia Sinica

Jia-Wei Shao Shanghai Astronomical Observatory

Mikhail Shaposhnikov EPFL, Switzerland

Bo-Wen Shi Department of Physics, Nanjing University, Nanjing

Maresuke Shiraishi Nagoya University

Arunansu Sil IIT, Guwahati, India

Yong-Seon Song Korea Astronomy and Space Science Institute

Albert Stebbins Fermilab

Gang Su University of Chinese Academy of Sciences

Shi-Chun Su DAMTP, Cambridge

Meng Su Harvard/MIT

Abril Suárez Cinvestav

Lei Sun NAOC

Cheng-Yi Sun Institute of Modern Physics, Northwest Univ. Xi

Teruaki Suyama The University of Tokyo

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Olli Taanila Bielefeld University

Tomohiro Takesako ICRR, University of Tokyo

Norihiro Tanahashi University of California, Davis

Charling Tao CPPM/THCA

Gianmassimo Tasinato ICG, University of Portsmouth

Hai-Jun Tian NAOC

Yue-Lin Tsai National Centre for Nuclear Research

Jon Urrestilla University of the Basque Country, Spain

Wessel Valkenburg Leiden University

Hermano Velten Bielefeld University / UFES (Brazil)

Alexander Vikman CERN

Raymond Volkas The University of Melbourne

David Wands University of Portsmouth

Ling-Fei Wang Lancaster University

Hong-Xin Wang Department of Physics, Nanjing University

Yu-Ting Wang Uni. of Portsmouth and Dalian Uni. of Technology

Fa-Yin Wang Nanjing University

Tao Wang East China Normal University

Yi Wang McGill University

Qing Wang Dept of Phys, Tsinghua Univ.

Xin Wang Nanjing University

Qiao Wang NAOC

Ying-Lin Wang NAOC

Jan Weenink Utrecht University

Hao Wei Beijing Institute of Technology

Christoph Weniger Max-Planck-Institut für Physik, München

Yvonne Wong RWTH Aachen

De-Jun Wu University of Chinese Academy of Sciences

Yue-Liang Wu UCAS/KITPC/ITP

Shu-Mei Wu NAOC

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Ping Xi Shanghai Normal University

Bing Xi Shanghai Normal University

Li-Xin Xu Dalian University of Technology

Yi-Dong Xu NAOC

You-Hua Xu NJU/NAOC

Xun Xue East China Normal University

Bing-Kan Xue Princeton University

Daisuke Yamauchi ICRR, University of Tokyo

Chang-Shuo Yan NAOC

Xiao-Feng Yang Nanjing University

Xin-Juan Yang SHAO

Wuernisha Yimingniyazi Xinjiang University

Peng-Fei Yin IHEP

Jun'ichi Yokoyama RESCEU, The University of Tokyo

Bo Yu Purple mountain observatory

Zhao-Huan Yu IHEP

Yun-Chuan Yu NAOC

Qiang Yuan IHEP

Bin Yue NAOC

Moslem Zarei Isfahan University of Technology

Ivonne Zavala University of Groningen

Jing Zeng SHAO

Hu Zhan NAOC

Tong-Jie Zhang Department of Astronomy, Beijing Normal University

Xin-Min Zhang IHEP

Yun Zhang Nanjing University

Zhao-Xi Zhang Institute of Theoretical Physics

Ke-Chao Zhang ITP

Xiao-Xia Zhang NAOC

Fu-Peng Zhang NAOC

- 78 -


Jiao Zhang NAOC

Gong-Bo Zhao NAOC/Portsmouth

Dong-Yao Zhao NAOC

Wei Zheng Department of Physics, Nanjing University

Yun-Long Zheng Nanjing University

Yi Zheng SHAO

Chen Zheng ITP

Yu-Feng Zhou ITP

Lan-Jun Zhou ITP

Jie Zhou NAOC

Hong-Ming Zhu NAOC

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