Primordial fluctuations 20  Isotropic 3K background. The most perfect blackbody we know Dipole (3.4 mK). Our motion relative to CMB

Boomerang

In search of acoustic peaks…

What do we already know? 1.The usual stuff: Universe is flat. Since low matter content, there is a cosmological constant (ie. dark energy).

What do we already know? Presence of harmonic oscillations: coherence of initial fluctuations Strong evidence for either inflation (or a structure formation scenario that is rapid in time). Alternative scenarios for structure formation, such as cosmic defects, are ruled out. The not so usual stuff:

In search of acoustic peaks… MAP COBE

… and more peaks

The promised land…. (with Planck) Hu & Dodelson (Annual Reviews 2002)

After Acoustic Peaks: Next Generation CMB Asantha Cooray Caltech Structure Evolution and Cosmology - October 31st, 2002

Cosmic Time Line

What else can we do with CMB?

I. Determine the energy scale of inflation CMB Polarization The role of confusions: weak lensing With confusions partly removed

CMB Polarization Polarization is described by Stokes-Q and -U These are coordinate dependent The two dimensional field is described by a gradient of a scalar (E) or curl of a pseudo-scale (B).

CMB Polarization Polarization is described by Stokes-Q and -U These are coordinate dependent The two dimensional field is described by a gradient of a scalar (E) or curl of a pseudo-scale (B). Grad (or E) modes Curl (or B) modes (density fluctuations have no handness, so no contribution to B-modes) Kamionkowski et al. 1997; Seljak & Zaldarriaga 1997

Grad or E modes Temperature and Polarization quadrupole

Keating et al (Zaldarriaga 1997) Grad or E modes: Reionization

Gravitational-waves Inflation predicts tensor perturbations due to primordial gravity waves Hard to detect with temperature information alone (contribute to large angle anisotropies, dominated by cosmic variance) Distinct signature in polarization (in terms of curl, or magnetic-like, modes)

Gravitational-waves

What else can we do with CMB? I. Determine the energy scale of inflation CMB Polarization The role of confusions: weak lensing With confusions partly removed

Why confusions? z ~ ? Structure formation today We are collecting photons from the last scattering surface

Gravitational Effects Scattering Effects (via electrons) Frequency shifts Lensing deflections Time-delays z ~ ? Structure formation today late-time universe: non-linear physics. Large scale structure modifies CMB properties Why confusions?

Gravitational Effects Geometric effect  Angular deflection of Photons Potential effect  Time delay of photons (Seljak 1996; Zaldarriaga 2000; Hu 2000; Hu & Cooray 2000 and many more before) Lensing and time-delay Two effects combined lead to the Fermat potential

Gravitational Effects Geometric effect  Angular deflection of Photons Potential effect  Time delay of photons (Seljak 1996; Zaldarriaga 2000; Hu 2000; Hu & Cooray 2000 and many more before) Lensing and time-delay Two effects combined lead to the Fermat potential

Gravitational Effects (Seljak 1996; Zaldarriaga 2000; Hu 2000; Hu & Cooray 2000 and many more before) Lensing and time-delay Things needed 1. Large scale structure deflections 2. CMB angular gradients

Cooray 2002

Contribution can be described as a result of effects in two regimes: Large scales: fluctuating CMB gradients modulated by large scale - slowly varying - mass fluctuations Small scales: constant CMB gradient lensed by small scale mass fluctuations (smoothing and shifting of power )

Cooray 2002 Also in Polarization… Lensing mixes Stokes-Q and U, or alternatively, between E and B. (Seljak & Zaldarriaga 1998)

Curl modes: Gravitational-waves and lensing

Lensing vs. Gravitational-Waves: Which dominates?

After Planck??? Sensitivity less than 1/50th Planck with same beam… Lensing contribution detect with S/N~many hundreds.

Temperature field Weak Lensing in CMB Hu 2002

Temperature field Lensed temperature field Weak Lensing in CMB Hu 2002

Quadratic Statistics as a way to reconstruct lensing deflections Reconstruction algorithm (basics) Lensing effect is on the second order - has to be a quadratic statistic CMB maps are noise dominated - has to be able to understand noise properties easily and be able to extract most information on lensing

Squared Temperature-Squared Temperature Power Spectrum Hu 2001 Hu & Okamato Cooray & Kesden 2002 Input deflection (mass) field Constructed deflection map with 1.5 arcmin beam and 27 arcmin noise CMB as a weak lensing experiment (Other suggestions: temperature gradients Seljak & Zaldarriaga; Bernardeau et al.) Hu 2001

Detection of lensing potential power spectrum with Planck Seljak & Zaldarriga 2000; Hu 2001; Cooray & Kesden 2002 Quadratic Statistics as a way to reconstruct lensing deflections

Cooray 2002 Lensing convergence CMB as a weak lensing experiment Z~1000 Z~1

Cooray 2002 Lensing convergence CMB as a weak lensing experiment Z~1000 Z~1 Why do this? 1.Source redshift is known (recombination) 2. Linear power spectrum - (cosmology) 3. Test evolution 4. Get this for free (no need for a CMB version of LSST)

Cooray 2002 Hu 2002 Lensing convergence CMB as a weak lensing experiment Z~1000 Z~1 Improvements to Parameters CMB lensingPolarization

Lensing Extraction Cooray & Kesden 2002 As a function of beamwidth with sensitivity of 1 microK/sec 1/2 Gaussian noise Additional non-Gaussian

Extract with a noise contribution below an order of magnitude of the signal (Kesden et al. 2002; Knox & Song 2002) Curl: Gravitational-Waves With CMB temp. data cleaned For lensing

Curl: Gravitational-Waves With CMB lensing reconstruction -> Reasonable S/N detection of gravitational wave B-modes (unconfused !!!) Post Planck mission (Planck noise/50, FWHM/3)

Kesden, Cooray & Kamionkowski 2002; also, Knox & Song 2002

Post-LISA mission (already a white paper to NASA SEU: GREAT by Cornish et al. Confusing backgrounds there is a separate issue)

Kesden, Cooray & Kamionkowski 2002 CMB polarization can be used to detect gravitational-waves Lensing of scalar modes confuses the gravitational-wave signal The lensing effect can be separated in a model-independent manner using the CMB temperature data alone

Kesden, Cooray & Kamionkowski 2002 CMB polarization can be used to detect gravity-waves Lensing of scalar modes confuses the gravity-wave signal The lensing effect can be separated in a model-independent manner using the CMB temperature data alone Proposal: If one is to detect gravitational waves, also make a high resolution map of the temperature towards the area surveyed in polarization

Thermal Sunyaev-Zel’dovich Effect This is Real! This is not, but we’ll get there…. Observations: Carlstrom et al. Simulations: Pen et al. The statistics in a wide-field SZ map? How to recover SZ from CMB?

Frequency Separation  Scattering moves photons from low frequencies (RJ part of the frequency spectrum) to high frequencies (Wien regime) In the language of Sunyaev-Zel’dovich (1980): Frequency shift the CMB blackbody and the difference (wrt to CMB)

Frequency Separation Back to basics: how can we separate SZ from CMB? In the language of Sunyaev-Zel’dovich (1980): Frequency shift the CMB blackbody and the difference (wrt to CMB) use frequency dependence of the SZ effect relative to CMB

Frequency Separation decrement increment SZ null ~ 217 GHz Back to basics: how can we separate SZ from CMB? use frequency dependence of the SZ effect relative to CMB

 combine experiments + known properties of foregrounds Frequency Separation Separation of SZ from CMB and rest in upcoming/present data With Planck sensitivity: Input SZ SZ+CMB+Foregrounds Recovered SZ What can we do with the recovered SZ map? Cooray, Hu & Tegmark 2000 (In real life, this is what we observe)

Can we measure the SZ power spectrum? one sigma detection limits for SZ or SZ-like effect. Thermal Sunyaev-Zel’dovich Effect Cooray, Hu & Tegmark 2000; Foreground separations in Tegmark et al. 1999; Bouchet & Gispert 1999; Knox 1999;

Results from recent SZ related data A2163:LaRoque et al Thermal SZ kinetic SZ Novel Application: Measure CMB temperature at high redshift

Results from recent SZ related data A2163:LaRoque et al Battistelli et al (MITO Collaboration) Thermal SZ kinetic SZ Novel Application: Measure CMB temperature at high redshift

Results from recent SZ related data CN molecules SZ clusters Coma A2163 Constrain T_CMB(z)=T_0(1+z) Battistelli et al. 2002; astro-ph/

Can we measure the SZ power spectrum? one sigma detection limits for SZ or SZ-like effect. Thermal Sunyaev-Zel’dovich Effect Cooray, Hu & Tegmark 2000; Foreground separations in Tegmark et al. 1999; Bouchet & Gispert 1999; Knox 1999; How to describe the SZ contribution due to large scale structure?

Halo Approach to Large Scale Structure Towards a better analytical model: Dark matter halo model for clustering: Complex View Simplified View Review article to appear in Physics Reports (Cooray & Sheth)

Halo Approach to Large Scale Structure Basic idea: 1.All dark matter in halos 2. Correlation functions can be described through correlations within and between halos 3. Ingredients: halo profile (NFW or variants) Mass function (Press-Schechter or variants) Halo bias model Two point function 2-halo 1-halo Dark matter halo model for clustering Neyman & Scott 1952; Peebles 1974; Scherrer & Bertschinger 1991; Seljak 2000; Ma & Fry 2000; Scoccimarro et al 2000; Cooray, Hu, Miralda-Escudé 2000;

Dark matter power spectrum Gas Profile Sigurdson & Cooray 2002; data from Santa Barbara Comparison Project

Dark matter power spectrum Temperature Profile Sigurdson & Cooray 2002; data from Santa Barbara Comparison Project

Temperature Profile Loken et al. 2002

Dark matter power spectrum Self-similar solution Sigurdson & Cooray 2002; data from various authors Temperature-Mass Relation

Extensions to SZ: Pressure power spectrum SZ  line of sight projection of pressure power spectrum Note: Poisson or single-halo term dominates the SZ power spectrum. Why? SZ effect: Pressure power spect. is sensitive to halos with high temperature electrons.  additional mass weighing compared to the dark matter power spectrum  Poisson term boosted relative to the halo correlations SZ Power Spectrum under the halo model

Results from recent SZ related data Sigma_8=0.9 Sigma_8=1.1 Non-Gaussian errors: Cooray 2001

Results from recent SZ related data Sigurdson, Cooray & Kamionkowski 2002 Is sigma_8 too high? Currently preferred~0.7 to 0.8

Results from recent SZ related data Sigurdson, Cooray & Kamionkowski 2002 |||||||||| Not dominated by Point Sources

Results from recent SZ related data

Future CMB There is more to CMB than just acoustic peaks Full talk and details at And why do we want to do this? Necessary to study inflation with polarization (e.g. remove lensing contribution) higher order effects can be used for further extraction and separation e.g., lensing studies with CMB