Special Astrophysics Seminar

Toward a precise measurement of weak lensing signals with CMB and galaxy observations: A theoretical developement and its cosmological implications

Toshiya Namikawa

University of Tokyo

Several cosmological observations in the last decade have successfully led to the establishment of a fundamental framework in cosmology. Taking seriously account of our current understanding and lack of our knowledge of the universe, the cosmology in the coming decade should focus on more advanced and fundamental issues. One of the powerful probe to tackle these fundamental issues is weak gravitational lensing; a deflection of photons emitted from, e.g., last scattering surface of CMB or galaxies.

In this talk, I show what can we probe by measuring weak lensing signals of CMB, especially focusing on odd-parity quantites, such as curl mode of deflection angle and B-mode shear. I also discuss our proposed estimator for CMB lensing reconstruction which is more robust than the current estimator with minimal loss of signal to noise.