Cosmological parameter and parity violation constraints using Cosmic Microwave Background polarization spectra measured by the QUaD instrument.

摘要

The QUaD instrument observed the Cosmic Microwave Background (CMB) in temperature and polarization for three austral winters from 2005 to 2007 on a roughly 120 square degree field. QUaD's 143 days of data from the last two seasons are processed, calibrated and analyzed to create high-resolution maps of the CMB and derive CMB spatial anisotropy spectra. QUaD is the first experiment to observe a number of harmonic peaks and troughs in the E-mode polarization spectrum to small scales, affirming our understanding of the plasma physics of the early universe and the ΛCDM model. Cosmological parameters are derived using Markov Chain Monte Carlo methods from QUaD data solely with the Hubble Key distance scale to quantify concordance with ΛCDM. QUaD data combined with other measurements of the CMB and large scale structure are also used to quantify QUaD's contribution to precision measurements of cosmological parameters, including a limit on the tensor-to-scalar ratio of r 0.20. QUaD establishes an upper limit on the conversion of polarization power by weak gravitational lensing of 0.77 micro K2 at 95% confidence, compared to the ACDM expectation value of 0.054 microK2. Finally, QUaD constrains the total possible rotation of the polarization directions of photons due to cosmological-scale electrodynamic parity violation to Deltaalpha = 0.82° +/- 0.49° (random) +/-0.50 (systematic). This is equivalent to constraining isotropic Lorentz-violating interactions to 10 -43 GeV at 95% confidence. QUaD produces the strongest constraint to date on cosmological-scale parity violating electromagnetic interactions.