July 2009MPA-Garching

Michael S. TurnerKavli Institute for Cosmological Physics

The University of Chicago

2009 Biermann Lectures:“Quarks and the Cosmos”

I. Cosmic Acceleration and Dark Energy (8 July) I. Inflation and Beyond (23 July)

II. Future Opportunities and Challenges (28 July)

• Contributions to the theory of convection in stars• Modeled the solar chromosphere and corona• Computed atomic physics parameters needed for stars• Predicted the solar wind (based upon comets) • Magnetic fields in the solar system and in the Galaxy

Where is he now?

Profound Connections

Between Quarks and the Cosmos

Basic Features of the Universe

tied to Fundamental

Physics

Michael S Turner

Cosmology Cosmology is is a a

young scienceyoung scienceits story only 300 years after its story only 300 years after

the invention of the telescopethe invention of the telescope

Michael S Turner

1916-1918: General Relativity & 1916-1918: General Relativity & ΛΛ

PS: Never mind Λ

Michael S Turner

1929: Just One Number K 1929: Just One Number K (error bars not needed, velocity in km)

Hubble & Humanson: few 100 galaxies, z < 0.1Hubble & Humanson: few 100 galaxies, z < 0.1

K (H 0) = 550 km/s/Mpc

Gamow’s Hot Big Bang“alpher, bethe, gamow,” 1948

1948: Steady State Theory

Michael S Turner

Cosmology: The Search for Cosmology: The Search for Two Numbers Two Numbers … Sandage 1970

Michael S Turner

Landau on Landau on CosmologistsCosmologists

Often in Error, Often in Error, Never in Doubt!Never in Doubt!

Michael S Turner

and at U Mass

The Redbook, a manual for faculty members that explained what a university was, and

what it wasn't. It cited two courses one wouldn't find in a curriculum of higher education: witchcraft and cosmology.

Michael S Turner

Discovery of Cosmic Microwave Background, 1964

Michael S Turner

““The Standard Model”The Standard Model”Hot Big Bang (circa 1972)Hot Big Bang (circa 1972)

““Reality (physics) Based”Reality (physics) Based”• BBN (nuclear physics)BBN (nuclear physics)• CMB (atomic physics)CMB (atomic physics)• Structure Formation (grav. Structure Formation (grav.

physics)physics)• Begins at 0.01 secBegins at 0.01 sec• ΩΩ00 ~ 0.1 (baryons) ~ 0.1 (baryons)Big QuestionsBig Questions• ““The naughts”: HThe naughts”: H00, t, t00, Ω, Ω00

• Large entropy per baryonLarge entropy per baryon• Hadron WallHadron Wall• Origin of density Origin of density

perturbationsperturbations

Michael S Turner

Michael S Turner

1980s: The Go Go Junk Bond Days 1980s: The Go Go Junk Bond Days of Early Universe Cosmologyof Early Universe Cosmology

““Creativity Based”Creativity Based”• InflationInflation• Cosmic StringsCosmic Strings• BaryogenesisBaryogenesis• Magnetic Magnetic

MonopolesMonopoles• Phase TransitionsPhase Transitions• Hot and Cold Dark Hot and Cold Dark

MatterMatter• Decaying ParticlesDecaying Particles• Kaluza-KleinKaluza-Klein

Michael S Turner

Two Really Important IdeasTwo Really Important IdeasThat Changed CosmologyThat Changed Cosmology

with deep connections between quarks and the cosmos

Inflation:Inflation: brief period of rapid (accelerated) expansion accounts for smoothness, flatness; heat of the big bang; and seed inhomogeneities

Particle dark matter:Particle dark matter: bulk of the dark matter that holds the Universe together resides in a sea of elementary particles left over from the big bang

Michael S Turner

Cold Dark Matter Transformed “Astrophysical Cosmology”

… and this Institute!

Michael S Turner

1990s: Beginning of Data-driven 1990s: Beginning of Data-driven CosmologyCosmology

• COBE! and CMB experiments• Redshift surveys (CfA, IRAS, 2dF, SDSS)• Large-scale velocity field measurements• Gravitational lensing• Big telescopes (Keck, …) with big CCD

cameras• HST, X-ray, gamma-ray, IR, …

Big Glass on the Ground: Big Glass on the Ground: 4 VLT, 2 Kecks, 2 Geminis and 4 VLT, 2 Kecks, 2 Geminis and

2 Magellans2 Magellans

Great Observatories in Space: Great Observatories in Space: Hubble, Spitzer, Chandra, and Hubble, Spitzer, Chandra, and

FermiFermi

How far can you see on a clear

day?Back to the birth

of galaxies

How far can you see on a clear day with x-ray eyes?To supermassive black holes at the

edge of the Universe!

Michael S Turner

2000s: Era of Precision Cosmology2000s: Era of Precision Cosmology

““Fisher Based”Fisher Based”• Cosmological

parameters• Tests of inflation, CDM• Correlating large,

complex data sets• Cosmological

Consistency• Physical parameters

(e.g., neutrino mass)

Michael S Turner

The Consensus CosmologyThe Consensus Cosmologydark matter, dark energy, inflation inspired

fits a large body of precision data!

Michael S Turner

The Universe circa 380,000 yrsThe Universe circa 380,000 yrsWMAP

±0.001% Fluctuations

Michael S Turner

Curve = concordance cosmology

Michael S TurnerSloa

n D

igita

l Sky

Sur

vey

sdss

.org

Large-scale structure: Distribution of 106 galaxies

in the Universe today

Michael S Turner

Tracing the history from a slightly lumpy Universe to galaxies ablaze

Michael S Turner

The “Consensus Cosmology”The “Consensus Cosmology”based upon precision measurements

• From quark soup to nuclei and atoms to galaxies and large-scale structure

• Flat, accelerating Universe• Atoms, exotic dark matter & dark energy• Consistent with inflation• Precision parameters

–Ω0 = 1.005 ± 0.006 (uncurved)–ΩM = 0.280 ± 0.013–ΩB = 0.045 ± 0.0015–ΩDE = 0.72 ± 0.015–H0 = 70 ± 1.3 km/s/Mpc–t0 = 13.73 ± 0.12 Gyr–Nν = 4.4 ± 1.5

Consistent with Consistent with all data, all data,

laboratory and laboratory and cosmological!cosmological!

Michael S Turner

Cosmic Acceleration is a central feature of the

consensus cosmology

no cosmic acceleration, no consensus cosmology!

Discovery! – 1998Discovery! – 1998

Hi z Supernova TeamSupernova Cosmology Project

Mark Philips

Two Technological Enablers:Two Technological Enablers:

1.1. Large (100 Mpixel) CCD Large (100 Mpixel) CCD CamerasCameras

2.2. SNe Ia: Bright, SNe Ia: Bright, Standardizable Candles (1.4 solar mass bomb)

The Discovery DataThe Discovery Data

Perlmutter et al, 1999 Riess et al, 1998

Carl Sagan:Carl Sagan:

Extraordinary Extraordinary Claims Claims RequireRequire

Extraordinary Extraordinary EvidenceEvidence

… … in any case, the in any case, the extraordinary evidence is extraordinary evidence is

now in placenow in place

Michael S Turner

Curve = concordance cosmology Ω0 = 1.005 ± 0.006 ΩM = 0.28 ± 0.015

only consistent ifΩΛ-like = 0.72 ± 0.015

1000 SNe from: 1000 SNe from: the original teams + the original teams +

SNLS, ESSENCE, SDSS, SNLS, ESSENCE, SDSS, CfA, CSP, …CfA, CSP, …

More data stronger signalMore data stronger signal

SDSS-II Supernova SurveySDSS-II Supernova Survey

~500 Well studied SNe Ia, suitable for framing

Evidence for past acceleration: Evidence for past acceleration: Important reality checkImportant reality check

HST ACS Sample of high-z SNe: A. Riess et al, Ap.J 607, 665 (2004)

Michael S Turner

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Baryon Acoustic Oscillations (BAO): Zel’dovich’s Standard Ruler

Clusters as Standard RulersClusters as Standard Rulers

Use constancy of the baryon-to-total

mass ratio as a standard ruler

S. Allen et al, MNRAS 353, 457 (2004); 383, 879 (2007)

Michael S Turner

New stand alone evidence for cosmic acceleration from

clusters observed by Chandra

A.Vikhlinin et al, ApJ 692, 1060 (2009) [arXiv:0812.2720]36 Clusters w/<z>~0.55 and 49 w/<z>~0.05

Michael S Turner

Michael S Turner

Consistent with all observations:

ΩΛ = 0.71 ± 0.02

Consistent Age for UniverseConsistent Age for Universe

EddingtonEddingtonCriterionCriterion

Very elastic stuff (p < -ρ/3) with repulsive

gravity is called “dark

energy”

Dark EnergyDark EnergyDefining features:• Large negative pressure, p ~ -ρ, so that (ρ + 3 p) < 0• w = p/ρ (equation-of-state parameter) ~ -1• Smoothly distributed• Not particulate (dark matter has p ~ 0)

Simplest example: • Energy of the quantum vacuum: w = -1

The Gravity of Nothing

Is Repulsive

… But How Much DoesNothing Weigh?

Apparently, Way Too Much

or Possibly Nothing

to be more precise, the answer is nonsensical

(infinite) – not as bad as a finite answer that is off by

orders of magnitude

ρvac ≈ 3 x 10-11 eV4

Vacuum Energy Problem Solved Vacuum Energy Problem Solved by Supersymmetry or ?by Supersymmetry or ?

Now we have two puzzles:

Why does nothing weighs so little?&

What is dark energy?

Puzzles could be related or unrelated!

Theorists: When in

doubt, just add a

scalar field

NB: does not address of the

lightness of nothing

“Old Gravitational Physics” Hitherto Undiscovered Aspects of GR?

• Primordial inflation explains why the universe is accelerating today, E. W. Kolb, S. Matarrese, A. Notari, A. Riotto (astro-ph/0503117)

• On cosmic acceleration without dark energy, E.W. Kolb, S. Matarrese, A. Riotto (astro-ph/0506534)

• Comments on Backreaction and Cosmic Acceleration, E. Kolb, S. Matarrese, A. Riotto (astro-ph/0511073)

• Cosmological background solutions and cosmological backreactions, E. Kolb, V. Marra, S. Matarrese, (arXiv: 0901.4566)

Dark Theory Summary

• Can easily accommodate cosmic acceleration (meets Eddington criterion)

• No satisfactory or even compelling explanation (lots of interesting ideas)

• “GR exceptionalism” (hard to create a viable alternative)

• Very important problem

Why dark energy is importantWhy dark energy is important Not in the list of players in the standard model

(new physics) Non-particulate (counterexample to the 2000 yr

reductionist approach), repulsive gravity Could be related to inflation or dark matter or both

or neither! May have other effects (long range forces,

neutrino mass) Controls the destiny of the Universe (though

probably not evolution of structure etc)

From Here to EternityFrom Here to Eternity

Cannot Understand Our CosmicDestiny Until We Understand What

Dark Energy Is!

In the Presence of DarkEnergy, a Flat UniverseCan Expand Forever, Re-collapse, or EvenExperience a Big Rip!

Youbetcha Katie, I believe

in Dark Energy – we can see it from Alaska!

Current null hypothesis (Λ/quantum vacuum energy) is not acceptable (maybe enough for astrophysical

cosmologist).It is a signal for new physics: gravitational, particle, or ? And

fundamental to our understanding of the cosmological framework

Important clue or

coincidence?At the very

least, we can now say that cosmology is the battle between two dark titans

Two Big Dark QuestionsTwo Big Dark Questions

Does Dark Energy change with time (i.e., is dark energy vacuum energy)?

Does Cosmic Acceleration require going beyond General Relativity?

No, at the 10 to 20% level

Not well tested

Probing Cosmic Acceleration Probing Cosmic Acceleration and Dark Energyand Dark Energy

• Primary effect is on the expansion rate

• Expansion rate controls distances, structure growth

• Two Qualitatively Different Probes– Geometric: distances– Dynamic: growth of structure – NB: if not GR, changes in growth, lensing

Known Probes of Dark EnergyKnown Probes of Dark Energy• Supernovae: Geometric• BAO: Geometric + simple physics• Weak Lensing: Geometric + dynamic• Clusters: Dynamics + geometric• Evolution of large-scale structure (dynamic)

– Must reproduce LCDM– Growth factor/red-shift space distortions

• CMB and other precision data that pin down cosmological parameters (provide priors)

Dark Energy:ΩDE = 0.76 ± 0.02 w = -0.94 ± 0.1

(± 0.1 sys)

Where We Are Today

New Results 400d SurveyNew Results 400d SurveyAlexey Vikhlinin et al, CCCP

Allow w to vary:

w = w0 + wa(1-a) a = scale factor

ΩDE = 0.76 ± 0.02 w0 = -1 ± 0.2

wa ~ 0 ± 1Possible variation is not well constrained

No Reason to Believe w is Constant

• Observational side– >1000 SNeIa; better studied (more colors, esp. IR, spectra,

better LC coverage)– Warts yes; cancer no

• Theoretical side– Significant improvement in handling of combustion; ignition

mechanism still a big issue (source of diversity?)– Producing more observables– Evidence for 1.4 Msun explosion– Tests for and models of SNeIa outliers

• Issues– Dust, percent level photometry, need larger local sample/training

set; demographics, outliers, – Better theoretical understanding

Supernovae: Significant ProgressSupernovae: Significant Progress

Pandora’s Box and SNeIa

OR

Clusters:Cosmic Frogs: very sensitive

to cosmic environment

• Observational side– Big surveys underway (ACT, SPT)– First blind detections of clusters (SPT)– Results from 400d: constraints to w & stand alone evidence for

DE– Clusters can be found by O, X, and SZ

• Theoretical side– Exponential leverage!– Significant progress on understanding mass/observable relations

and formation history

• Open issues– Robustness of mass/observable relations– Selection– Cluster physics: how much more than

ClustersClusters

Staniszewski et al, astro-ph/0810.1578

First Results from the South Pole Telescope

Michael S Turner

eROSITA 2011

• Observational side– Two (three) detections with 4% errors!– Big surveys underway– Need lots of “spectroscopic class” red shifts

• Theoretical side– Powerful & clean; good probe of curvature– Geometric + “simple physics”

• Open issues– Exploit other scales (damp, Silk)– Systematics: what are they??; how bad?? Small

compared to 1%

BAOBAO

• Observational side– Steady progress ( 100 sq deg): signal out to 4

degrees (CFHTLS), on the way to 1000 sq deg and beyond

– mild constraints on w; WMAP tension on σ8 gone• Theoretical side

– Theory well understood, but γ ~ σ8 ΩM0.4 z0.8 |w|0.15

– Shear ratio test isolates geometric side• Issues

– Better knowledge of non-linear power spectrum– Systematics (image, photo-z: δw ~ 15δz) – see

Taylor

Weak LensingWeak Lensing

• BAO: SDSS/2dF, WiggleZ, FMOS, BOSS HETDEX, WFMOS, PAU

• CL: SZA, SPT, DES, ACT, 400d, eROSITA• SNe: JDEM, DES, PanSTARRS• WL: PS, JDEM, EUCLID, DES, PanSTARRS• CMB et al: WMAP/ACT/SPT/Planck – cosmological

degeneracies make many other observations valuable

On the way to few % in w0, 10% in wa, significant tests of underlying gravity theory … and deeper understanding of dark energy

Impressive Array of Dark Energy Impressive Array of Dark Energy Projects on the HorizonProjects on the Horizon(pssst, don’t tell Simon “DM” White)

Dark SummaryDark Summary• Strong evidence for cosmic acceleration, central

part of consensus cosmology• Theory provides a framework for discussing, but

not understanding• Profound problem whose solution is likely to

have far reaching consequences• Powerful probes: Clusters, SNe, BAO, WL +

Planck priors • Cosmic complementarity:

– Kinematic and dynamic probes; error ellipses– Expt’l complementarity: different systematics/risks

• Open mind to new ideas: long range force

Michael S Turner

How Much is Enough?!#How Much is Enough?!#

Michael S Turner

Four “Stage IV” FuturesFour “Stage IV” Futures

1. w = -1 & theory breakthrough

Percent level measurements of w and wa and LSS consistent with ΛCDM

+Theoretical understanding of small vacuum

energy

=

Problem Solved for Cosmologists and Particle Physicists

2. “w = -1” & theory breakthrough

Percent level measurements of w and wa and LSS consistent with ΛCDM

+New compelling theoretical prediction for time

variation of w and/or wa – just beyond the reach of Stage IV

=Problem Solved for Cosmologists,

Particle Physicists think about Stage V

3. “w ≠ -1” or wa ≠ 0

Detection of signature that DE is not vacuum energy

Potential implications for both particle

physics and cosmology=

With or without theoretical breakthroughboth Cosmologists, Particle Physicists think about what to measure in Stage V

4. w = -1 & no theory breakthrough

Percent level measurements of w and wa and LSS consistent with ΛCDM

+No theoretical understanding of small vacuum

energy=

Problem solved for cosmologists, but not for particle physicists

“Time out”: take a break and think hard about what to do next

ΛΛ’s Checkered History’s Checkered History

• 1917 – 1929– Einstein: static, finite, positively curved Universe

ρM = 2ρΛ, R = 1/(4πG ρM)1/2

– de Sitter (1917): vacuum solution, first derivation of Hubble’s Law

– Eddington-Lemaitre long lived cosmologies– Hubble discovers expansion– Einstein: “my greatest blunder”– Eddington remains obsessed

Early ConfusionEarly Confusion

• 1948 – 1970 – Bondi & Gold, Hoyle: Steady State Cosmology:

“perfect cosmology”– Strong signs of evolution: quasars, radio sources

and CMB kills a beautiful theory– Petrosian, Salpeter & Szekeres (abudnace of z ~ 2

QSOs) and Gunn & Tinsley (data)– Rise of Standard Cosmology (Hot Big Bang)

RevivalsRevivals

• 1930s: Pauli, “Size of Universe could not reach to the moon”

• 1968: Zel’dovich articulates the problem• 1989: Weinberg, “Bone in the throat of

theorists”

Quantum Vacuum Energy: Quantum Vacuum Energy: Most Embarrassing Problem Most Embarrassing Problem

in all of Physicsin all of Physics

• 1981 – 1984: Inflation & CDM• 1984 on – “Ω problem”• 1984 – 1995: Λ solution, best fit

Universe, COBE and ΩM ~ 0.3 & triumph of ΛCDM

• 1998: The Accelerating Universe• 1998: Cosmology Solved Debate• 1998: Birth of Dark Energy

and a new puzzle

Most Anticipated Surprise EverMost Anticipated Surprise Ever

Rapid acceptanceit is the missing piece of the puzzle

Quarks and the Cosmos