Project: Testing CMB delensing
Supervisor: Dr Benoit-Lévy (email@example.com)
Room O124B, 1st floor, Kathleen Lonsdale Building
Phone +44 20 7679 7689
Gravitational lensing is the bending of light as it passes near massive clumps of matter. This effect is widely known on the images of distant galaxies but also affects the furthest light we can observe: the Cosmic Microwave Background. Gravitational lensing therefore modifies the statistical properties of the observed CMB in a characteristic way that can be used to efficiently reconstruct the lensing potential, i.e., the distribution of matter projected on the sky. This effect has recently been measured at very high significance by the Planck Collaboration.
However, CMB lensing also generates a polarization signal that will be a contaminant for the next generation of CMB experiments aiming to detect the polarization signal predicted by inflationary theories. This project will therefore focus on the delensing operation: is it possible to de-lens the observed CMB maps with the reconstructed lensing potential, and then reduce the level of contamination produced by CMB lensing?