Constraining statistical anisotropy and parity violation using the cosmic microwave background and other probes
Dagoberto Contreras (UBC)
July 25, 2016
Abstract: This talk will be given in two parts. The first will concern one of the well known CMB ‘anomalies’, namely the hemispheric asymmetry (or dipole modulation). I’ll first recap the well known asymmetry signal in temperature, commenting on how its significance has been debated in the literature. I will then present a formalism necessary to translate the signal in temperature to other probes such as polarization, cmb lensing, or 21cm etc., in the hopes of determining if the ‘anomaly’ points to new physics or simply a statistical fluke. The second part will concern the latest constraints on the cosmic polarization rotation (often referred to as cosmic birefringence) from Planck. Planck now has the best limits on the uniform rotation of polarization. These constraints are now systematics dominated and will be difficult to improve upon.