State of the Universe

David Spergel Edinburgh October 24, 2007

We now have a standard cosmological model

   General Relativity + Uniform Universe Big Bang  Density of universe determines its fate + shape Universe is flat (total density = critical density)  Atoms 4%   Dark Matter 23% Dark Energy (cosmological constant?) 72% Universe has tiny ripples    Adiabatic, scale invariant, Gaussian Fluctuations Harrison-Zeldovich-Peebles Inflationary models

Thermal History of Universe

r radiation matter IONIZED NEUTRAL 10 4 10 3 z

Growth of Fluctuations

•Linear theory •Basic elements have been understood for 30 years (Peebles, Sunyaev & Zeldovich) •Numerical codes agree at better than 0.1% (Seljak et al. 2003)

Sunyaev & Zeldovich

CMB Overview

  We can detect both CMB temperature and polarization fluctuations Polarization Fluctuations can be decomposed into E and B modes q ~180/ l

ADIABATIC DENSITY FLUCTUATIONS

ISOCURVATURE ENTROPY FLUCTUATIONS

Determining Basic Parameters

Baryon Density

W b h 2 = 0.015,0.017..0.031

also measured through D/H

Determining Basic Parameters

Matter Density

W m h 2 = 0.16,..,0.33

Determining Basic Parameters

Angular Diameter Distance

w = -1.8,..,-0.2

When combined with measurement of matter density constrains data to a line in W m -w space

Predictive Theory Motivates Precision Measurements

 COBE measurement of spectrum (1990) and detection of large scale fluctuations (1992)  Detection of first acoustic peak (TOCO [Miller et al. 1999])  Rapidly improving ground and balloon-based measurements (1999-2002)  First peaks (TOCO, BOOM, DASI, …)  EE (DASI)  Wilkinson Microwave Anisotropy Probe (2003)  TT & TE

Wilkinson Microwave Anisotropy Probe

A partnership between NASA/GSFC and Princeton

Science Team:

NASA/GSFC Chuck Bennett (

PI

) -> JHU Michael Greason Bob Hill Gary Hinshaw Al Kogut Michele Limon Nils Odegard Janet Weiland Ed Wollack Brown Greg Tucker UBC Mark Halpern UCLA Ned Wright Chicago Stephan Meyer Princeton Chris Barnes Norm Jarosik Eiichiro Komatsu Michael Nolta Lyman Page Hiranya Peiris Rachel Bean David Spergel Olivier Dore Licia Verde Jo Dunkley

K - 22GHz

Ka - 33GHz

Q - 41GHz

V - 61GHz

W 94GHz

Q band V band W band

Fluctuations Appear to be Gaussian

  No evidence for local non Gaussianity  Three-point function  Minkowski functionals Claims of non-isotropy in fluctuations    Foreground contamination?

Statistical flukes (2-3 s ) Requires further investigation

Consistent Cosmology

 Large-scale structure  Cluster counts  Weak Lensing  Strong Lensing  Stellar Ages  Big Bang Nuclesynthesis (Li?)  Hubble Constant  Velocity Fields  Small-scale CMB Oguri et al. 2007 Kuo et al. 2007 Kuo et al. 2007

Limber Equation

Baryon Oscillations

CMB C( q ) C( q ) Baryon oscillation scale q 1 o Galaxy Survey (weaker effect) Selection function q photo-z slices

Baryon Oscillations as a Standard Ruler

 In a redshift survey, we can measure correlations along and across the line of sight.

 Yields

H

(

z

) and

D

A (

z

)!

[Alcock-Paczynski Effect] d r = D A dq d r = (c/H) d z Observer

SDSS and Baryon Wiggles

 Purely geometric test (SDSS + WMAP) QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture.

QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture.

Eisenstein et al. (2005)

SDSS-III

   SEGUE-2 (galactic photometry) MARVELS (multi-object exoplanet RV) APOGEE (R~10,000 IR spectroscopy of 100,000 stars)  Baryon Oscillation Sky Survey    Redshifts of 1.5 million LRGs (0.2 < z < 0.8) over 10,000 square degrees Lyman a absorption towards 160,000 quasars Instrument upgrade (higher throughput) • Switch to LBNL 4K x 4k fully depleted chips (red) and Fairchild chips (blue). Replace gratings with volume phase holographic grisms.

ADEPT

 Redshift survey of 100 million galaxies 1 < z < 2     Nearly cosmic variance limited across sky BAO, power spectrum, general astrophysics  Calibrates LSST redshifts, IR imaging (H ~ 23) Slitless spectroscopy 1.3 - 2.0 m m H a 2 m m Hawaii HgCdTe 2k x 2k chips

ACT:The Next Step

    Atacama Cosmology Telescope Funded by NSF Will measure CMB fluctuations on small angular scales Probe the primordial power spectrum and the growth of structure

ACT COLLABORATIONS

Government Labs Schools Museums Cat Ó lica PENN Haverford Princeton CUNY Toronto

…united through research, education and public outreach.

Simulations of mm-wave data.

1.4

0

150 GHz SZ Simulation MAP MBAC on ACT 1.7’ beam 2X noise PLANCK PLANCK

 1% Survey area  2% High quality area

Cosmic Timeline for ACT Science

• First galaxies • Universe is reionized • Ostriker-Vishniac/KSZ • Surveys of Sunyaev-Zel’dovich (SZ) clusters • Diffuse thermal SZ • Extraction of cosmological parameters • Initial conditions for structure formation z = 1000 t = 4 x 10 4 yrs z = 7 t = 3 x 10 6 yrs • N(mass,z) – Evolution of Cosmic Structure • Lensing of the CMB • The growth of structure is sensitive to w and m n • Additional cross-checks from correlations among effects z = 1 t = 1 x 10 9 yrs z = .25

t = 12 x 10 9 yrs now Primary CMB CMB Lensing OV/KSZ Diffuse Thermal SZ Cluster Surveys

  

Cross-Correlating Lensing and CMB

CMB provides a source plane at z = 1100 with very well determined statistical properties (but poorer statistics) CMB + Quasar & Galaxy Counts will measure bias CMB lensing+ Galaxy lensing cross correlation improves parameter measurements by roughly a factor of 3 (Mustapha Ishak) CMB + SN

Add Lensing

CMB + Lensing X-correlate

Cosmology Now Has A Standard Model

 Basic parameters are accurately determined   Many can be measured using multiple techniques CMB best fit now consistent with other measurements  Mysteries remain: dark matter, dark energy, physics of inflation  Next step: Probe Physics Beyond the Standard Model

THANK YOU !

Quick History of the Universe

  Universe starts out hot, dense and filled with radiation As the universe expands, it cools. • During the first minutes, light elements form • After 500,000 years, atoms form • After 100,000,000 years, stars start to form • After 1 Billion years, galaxies and quasars

CMB Polarization

    Weak signal  signal is statistical rather than a detection in each pixel Foregrounds  Synchrotron (dominant)  Dust Systematic Uncertainties Significant uncertainty in reionization redshift    Will improve with more data Polarization auto-correlation Dt/t ~0.1 in 4 year data

Polarization Measurements

  New window into Early Universe    Gravity waves from inflation Reionization Constraints on isocurvature admixtures, ionization history, etc.

CMB Polarization Measurements      Upcoming WMAP release BOOMERANG Polarization flight Lots of exciting ground and balloon experiments under development Planck CMBPOL

CMB Polarization: Another Dark Energy Probe

   When combined with optical measurements, this will enable us to cleanly measure the growth rate of structure: an independent probe of the properties of the dark energy Polarization lensing/ISW cross-correlation will enable us to probe the properties of dark energy at z~5-50 -- an epoch inaccessible to other experiments Small scale polarization experiments point the way towards the detection of gravity waves

W 94GHz

Is the Universe Finite or Infinite?

Topology

Two Torus

Other Tilings

Three Torus

Same idea works in three space dimensions

Infinite number of tiling patterns

This one only works in hyperbolic space

Spherical Topologies

This example only works in spherical space

Dodecahedral Space

Tiling of the three-sphere by 120 regular dodecahedrons

Homogeneous & Isotropic Universe

The microwave background in a multi-connected universe

Matched circles in a three torus universe

If the universe was finite:

Cornish, Spergel, Starkman, Komatsu

What we see in the WMAP data:

UNIVERSE IS BIG!

Conclusions

 Cosmology is in a golden age!

 Advances in technology are enabling us to probe the physics of the very early universe and the birth of structure  So far, the standard model appears to fit the data, but stay tuned!

Pen, Seljak, Turok astro-ph/974231 ACTIVE ISOCURVATURE MODELS

Key Historical Papers

Acoustic Peaks   Sunyaev & Zeldovich, ApSS, 7, 3 (1970) Peebles & Yu, ApJ 162, 815 (1970) CDM  Peebles ApJ 263, L1 (1982) proposed cold dark matter Lambda     Gunn & Tinsley (1975) Turner, Steigman & Krauss (1984) Peebles ApJ 284, 439 (1984) Supernova papers

Key Technological Step: Revolutionary CMB Cameras (multiplexed, filled arrays of thousands of bolometers)

•Planning three 1024-element arrays for fine-scale CMB on ACT: the MBAC.

32 mm

•Propose 4000-element polarized camera for ACT to round-out science return via lensing and inflationary probe.

Completed “close-packed” 12x32 bolometer array Torsional yoke attachment 1 mm SHARC II 12x32 Popup Array

Too Many Bumps and Wiggles?

  C 2 = 1.08 (3% probability) Need to include several systematic effects in error budget  Lensing of CMB   Beam variations & asymmetries 1/f noise non-Gaussian contribution to 4pt

More to Come….

      WMAP has effectively no lifetime limit Approved for 4 years of operation Improved TE + EE data will significantly improve t measurement More accurate 2nd and 3rd peaks Calibrate ground-based high l measurements Improvements in complementary measurements (SDSS, supernova[ACS, Carnegie, NOAO]) QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.

0.30

0.20

t

0.10

0,00 n s

Ground Based High Resolution Surveys

 Sunyaev-Zeldovich detections of clusters and hot intercluster gas  Ostriker-Vishniac fluctuations from z~5-20 from motions of reionized gas  Gravitational Lensing of CMB  Correlates with optical surveys, quasars  Probes mass fluctuations along line of sight

Too Little Large Scale Power?

 Lack of large scale power  Seen in COBE but clearer now    Is the universe finite?

Are we seeing a characteristic scale?

Is it just chance?

LCDM Best Fit Parameters

Wilkinson Microwave Anisotropy Probe

A partnership between NASA/GSFC and Princeton

Science Team:

NASA/GSFC Chuck Bennett (

PI

) Michael Greason Bob Hill Gary Hinshaw Al Kogut Michele Limon Nils Odegard Janet Weiland Ed Wollack Brown Greg Tucker UBC Mark Halpern UCLA Ned Wright Chicago Stephan Meyer Princeton Chris Barnes Norm Jarosik Eiichiro Komatsu Michael Nolta Lyman Page Hiranya Peiris David Spergel Licia Verde

60K line of sight 90K

WMAP

Spacecraft

upper omni antenna back to back Gregorian optics, 1.4 x 1.6 m primaries passive thermal radiator focal plane assembly feed horns secondary reflectors thermally isolated instrument cylinder 300K warm spacecraft with: - instrument electronics - attitude control/propulsion - command/data handling - battery and power control MAP990422 medium gain antennae deployed solar array w/ web shielding

WMAP Design Goal: Minimize Systematics A-B-A-B B-A-B-A •Differential design •milliK thermal Stability •Multiply linked scan pattern •Many cross-checks possible within data set One of 20

June 30, 2001

K - 22GHz

Ka - 33GHz

Foregrounds

  Synchrotron  Drops off sharply with n Dust  Finkbeiner Davis Schlegel template good fit  Free-Free  H a surveys (WHAM, VTSS, SHASSA)  Point sources   Measured through skewness Multifrequency power spectrum  Extrapolate source counts

FOREGROUND CORRECTED MAP

Angular Power Spectrum is Robust

 Same results for 28 different channel combinations  Same results for auto and cross-correlations  Same results for different weightings, analysis schemes

cosmic variance 1 deg

Temperature

85% of sky Best fit model

Temperature polarization

Simple Model Fits CMB data

Readhead et al. astro/ph 0402359

CMB & BBN

    CMB measures baryon/photon ratio Determines D/H ratio Helium   Was discrepant with CMB and D/H New neutron lifetime measurement removes problem Lithium   Sensitive to chemical evolution of Deuterium Early destruction QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture.

Model Predicts Universe Today

SDSS Tegmark et al. Astro-ph/0310723

Verde et al. (2003)

Evolution from Initial

WMAP team assembled

Conditions I

WMAP completes 2 year of observations!

DA leave Princeton WMAP at Cape

Evolving Initial Conditions II

Verde et al.

Evolution from Initial Conditions III

Verde et al.

CMB/LSS Correlation

   ISW  Confirms dark energy effects Sunyaev-Zeldovich  Trace gas pressure Seen in many surveys      SDSS 2 MASS Radio sources X-ray sources APM

W b h 2 W x h 2 h n s s 8

Consistent Parameters

WMAP+CBI+ ACBAR .023 + .001

All CMB(Bond) .0230 + .0011

CMB+ 2dFGRS .023 + .001

CMB+SDSS (Tegmark) .0232 + .0010

.117 + .011

.73 + .05

.117 + .010

.72 + .05

.121 + .009

.73 + .03

.122 + .009

.70 + .03

.97 + .03

.83 + .08

.967 + .029

.85 + .06

.97 + .03

.84 + .06

.977 + .03

.92 + .08

s 8

Consistency!

CMB + Lensing Contaldi et al. (2003) W  Hubble Constant  Baryon Abundance  Lensing Amplitude  Supernova Distance Scale  Cluster Abundances  Stellar Ages  Helium Abundance Spergel et al. 2003

New Questions

 Physics that we don’t know quantum cosmology,… (String theory,  How did the universe begin?

 What is the dark energy?

 Physics that we don’t know how to calculate (Non linear hydro, star formation…  First stars  Galaxy formation

Probing the Dark Energy

Detected only through Friedman equation: ?

How Can We Measure a(t)?

 Standard Ruler (angular diameter distance) CMB peak positions Matter power spectrum  Standard Candle  Supernova  Growth Rate of Structure  Gravitational Lensing

ISW Effect

 Measures the evolution of the potential on large scales  Detected through cross-correlations  SDSS     APM 2-MASS Radio Sources X-ray Sources QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture.

Nolta et al. 2005