Cosmology with gravitational lensing of the Cosmic Microwave Background | Colóquios DFMA

Resumo:

 

The Cosmic Microwave Background (CMB) is the most distant light that we can observe today. Since its emission roughly 380.000 years after the Big Bang it crossed all the Universe while coming to us. During their travel, the photons of the CMB have been deflected by the matter they crossed along their path, an effect called gravitational lensing. This deflection field of the CMB is a powerful observable, proportional to the integral of the matter distribution up to the early Universe. I will introduce how we can reconstruct this lensing field from CMB observations. I will then demonstrate how CMB lensing can put tight constraints on the content of the Universe, on the sum of the neutrino masses, and help us discover cosmic inflation. Lastly, I will introduce a new CMB lensing estimator, which will reconstruct optimally the lensing field for the next generation of CMB surveys.