Theoretical Physics Seminar: CMB lensing beyond the leading order: impact and detectability

by Dr Giovanni Marozzi (Centro Brasileiro de Pesquisas Físicas)

Thursday 18 May 2017, 15:00 → 16:00 Europe/Rome

Sala Riunioni (Dipartimento di Fisica e Astronomia)

In this seminar, I will present the weak lensing correction, to the cosmic microwave background temperature and polarization anisotropies, including all the effects that go beyond the leading order. These are: post-Born corrections, LSS corrections and, for the polarization anisotropies, the correction due to the rotation of the polarization direction between the emission at the source and the detection at the observer. I will then investigate the detectability of these contributions, comparing them with cosmic variance, and their impact on the estimation of cosmological parameters from future CMB experiments. In particular, I will present the impact of higher order lensing on the determination of the tensor-to-scalar ratio r and on the estimation of the effective number of relativistic species N_eff. Based on: GM, G. Fanizza, E. Di Dio and R. Durrer, JCAP 09, 028 (2016) [1605.08761]; 1612.07263; 1612.07650.