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Searching for the Polarizing Influence of Inflation. Or How I Learned to Stop Worrying and Love B-modes. Suzanne Staggs Princeton University. The Other CMB Power Spectra. The CMB must be polarized. (Martin Rees, 1968)
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Searching for the Polarizing Influence of Inflation Or How I Learned to Stop Worrying and Love B-modes Suzanne Staggs Princeton University
The Other CMB Power Spectra • The CMB mustbe polarized. (Martin Rees, 1968) • T and P must have correlations. (Coulson, Crittenden, & Turok, 1994) • P separates into E & B. (Seljak & Zaldarriaga, 1997; Kamionkowski, Kosowsky & Stebbins, 1997) • TE has been detected. (WMAP 2003 & DASI 2002) • EE has been detected. (DASI 2002: Kovac et al.) • BB has not. Note the log-log scale trick. predictions pre-WMAP! Hu & Dodelson (2002) (Abs(TE) labeled QE)
Polarization of the CMB is inevitable if anisotropies existat decoupling. (Must be quadrupolar; arise from Doppler shifts.)
WMAP 2003 DASI As you all know very well, the inevitable TE correlations have been detected!
The EE Mode also detected! And B is not: so far, a good thing. the WMAP model DASIdetections
WMAP predicts BIG(ger)B-modes! Note the log-log scale trick.
Peak B-mode: 200 nK rms Experimentalist Units: microK linear-linear plot total B-modes 200 nK 150 nK 100 nK B-modes from lensing 50 nK 0nK
Multipole, l Multipole, l Multipole, l EstimatedFOREGROUNDS IN ell-nu space COMING SOON: WMAP POLARIZATION MAPS IN FIVE COLORS
x a b y polarizers brute force… amplifers total power detector Ga Ea2 Gb Eb2 Ex Ey Ex ~ Ea + Eb OMT Ey ~ Ea - Eb correlation polarimeter ± Gx Gy ( Ea2 - Eb2 ) Coherent Receivers • Mitigates gain drift issues • allows fast phase switch
Detection Techniques • Coherent detectors: • Correlation polarimeters (CAPMAP, COMPASS) • interferometry (DASI, CBI) • WMAP-style correlation • (All polarization data published for the CMB in the last 2 decades relied on coherent methods.) • Bolometric detectors: • Rotating waveplates (avoids gain problem) • Stacked PSBs (Boomerang used them; folks seem happy!) • Planar antennas (allows dense focal plane in principle) • The next clever detection idea? • (Ultimately more sensitive and easier to scale to big N.)
* Compilation by Peter Timbie
CAPMAP • 12 W & 2 Q band receivers • 3’ beam probing l~500-1500 • in a 1º cap around NCP • Correlation polarimeters using • MMIC HEMT amplifers • 4W band deployed and • observing since early Jan Princeton D. Barkats, P. Farese, L. Hyatt, J. McMahon, S. Staggs Chicago C. Bishoff, M. Hedman D. Samtleben, K.Vanderlinde, B. Winstein Miami J. Gundersen, E. Stefanescu JPL T. Gaier
In future look for CONCLUSIONS HUGE bolometer arraysfor polarization & fine-scale CMB (ACT,SP,APEX) Polarizationdata are in the bag for: WMAP, more DASI, Boomerang (first PSBs!),CAPMAP, and (soon) MaxipolBig experiments building/designing: QUEST, BiCEP, POLARBEAR, +++ THE CMB HAS MORE TO REVEAL… maybe even B-modes.