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PIRSA:15040051

Inference of weak gravitational lensing signals from sky images

APA

Bernstein, G. (2015). Inference of weak gravitational lensing signals from sky images. Perimeter Institute. https://pirsa.org/15040051

Gary Bernstein

University of Pennsylvania

Talk number
PIRSA:15040051
Talk Type
Subject
Abstract

Weak gravitational lensing is a highly valued tool for inferring the structure of the spacetime metric between an observer and a cosmologically distant “wallpaper,” most commonly either the CMB or faint background galaxies. The best-measured quantities are the second derivatives of the projected scalar potential(s), which are manifested as apparent shearing and magnification of the wallpaper.  Given a collection of faint-galaxy images, what information can we extract about the shear and magnification that these images have undergone?  I will describe a new method of lensing inference that, unlike predecessors, is rigorously correct in the presence of noise and other observational realities, nearly optimal, and computationally feasible at the scale of current/future surveys like the Dark Energy Survey and the Large Synoptic Survey Telescope.