A Measurement of CMB Polarization with QUaD Sarah Church

Using the CMB to accurately measure cosmological parameters Straight-forward physics  accurate theoretical predictions with cosmological quantities as the free parameters Measurements are the key Precision measurements  “precision cosmology” Figure from WMAP; Bennett et al. 2003, Spergel et al. 2007

CMB polarization anisotropy Only quadrupoles at the surface of last scattering generate a polarization pattern Temperature Fourier mode Quadrupoles generated by: Velocity gradients in the photon-baryon fluid - SCALAR MODES (Vortices on the surface of last scattering - VECTOR MODES) Gravitational redshifts associated with gravitational waves - TENSOR MODES All pictures by Wayne Hu

E and B modes E modes B modes These modes retain their character on rotation of the local coordinate system E-modes are invariant under a parity change, B modes are not Scalar modes (density fluctuations) cannot generate B-modes Tensor modes generate a mixture of E and B modes

The CMB polarization power spectra Hu, Hedman, Zaldarriga, 2002 Temperature spectrum E-modes from scalar perturbations X100 fainter! Reionization bump Gravitationally lensed E-modes B modes from gravitational wave background spanning current limits and minimum detectable from CMB Hu & Okamoto (2001)

The QUaD Experiment First paper at arXiv:0705.2359 100, 150 GHz camera on 2.6m telescope Deployed at South Pole November 2004 Second season of observations finished October 2006 Third (final season) is underway First paper at arXiv:0705.2359

QUaD Focal Plane 1.5 deg 31 pixels: 12 at 100 GHz, 19 x 150 GHz Polarization sensitive bolometers (JPL/Caltech) Lines indicate direction of polarization sensitivity

QUaD Telescope Axis of rotation 2.64m on-axis Cassegrain 1.5 deg. FOV; Foam cone Secondary Primary Axis of rotation 2.64m on-axis Cassegrain 1.5 deg. FOV; 3.5’ beam FWHM @ 150 GHz, 5.2’ @ 150 GHz

First Season Data Recently Released 67 days mapping 60 square degrees of sky Maps opposite filtered to enhance l=200-1000 Submitted paper at arXiv:0705.2359 Processed data publicly available

Power spectra are consistent with -CDM

QUaD cosmological parameter estimates Using the polarization data only Using WMAP priors 0<bh2 <1 0<mh2 <1 0< <0.3 0.5<As<2.5 0<ns<2

Improvement expected from new data E-modes B-modes Projected error bars from actual Season II data A third season is underway Second year data release expected fall 2007

More sensitive experiments can probe B-modes from inflation r~0.01 QUIET, Planck (experiments with KIPAC role) r~0.001 Future experiment – Beyond Einstein Inflation probe? Expected range from inflation models involving supersymmetry (Kallosh) Log r D. Lyth, 2007