1. A Measurement of CMB Polarization with QUaD
Sarah Church

2. 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

3. 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

4. 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

5. 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)

6. 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:

7. 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

8. 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 150 GHz, 150 GHz

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

10. Power spectra are consistent with -CDM

11. 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

12. 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

13. More sensitive experiments can probe B-modes from inflation
r~ 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