Statistics of the CMB polarised anisotropies

TL;DR

This thesis investigates methods for estimating the polarized anisotropies of the CMB on masked skies, evaluates their effectiveness, and forecasts constraints on early universe physics such as tensor-to-scalar ratio, chiral gravity, and primordial magnetic fields.

Contribution

It demonstrates the efficiency of pseudospectrum methods for CMB polarization analysis and provides forecasts for detecting key signatures of early universe phenomena.

Findings

Pseudospectrum methods effectively correct E-to-B leakage.

Forecasts indicate potential detection of tensor-to-scalar ratio r.

Predictions for detecting chiral gravity and primordial magnetic fields.

Abstract

This PhD thesis (defended in 2014) is focused on the estimation of the CMB polarised anisotropies power spectra on a masked sky and on forecasts of constraints set on the primordial universe physics thanks to these anisotropies. After an introduction on the light polarisation, the standard model of cosmology and the CMB properties, I show the results obtained on the use and efficiency of pseudospectrum methods to correct for the so-called E-to-B leakage. Afterwards, I present the forecasts obtained on the detection of the tensor-to-scalar ratio r and on the detection of chiral gravity, using the pure pseudospectrum method. The study of forecasts of a primordial magnetic field detection using the CMB polarised anisotropies is finally briefly tackled.