An accurate and practical method for inference of weak gravitational lensing from galaxy images

Understand

We demonstrate highly accurate recovery of weak gravitational lensing shear using an implementation of the Bayesian Fourier Domain (BFD) method proposed by Bernstein & Armstrong (2014, BA14), extended to correct for selection biases.

• The BFD formalism is rigorously correct for Nyquist-sampled, background-limited, uncrowded image of background galaxies.
• BFD does not assign shapes to galaxies, instead compressing the pixel data D into a vector of moments M, such that we have an analytic expression for the probability P(M|g) of obtaining the observations with gravitational lensing distortion g along the line of sight.
• We implement an algorithm for conducting BFD's integrations over the population of unlensed source galaxies which measures ~10 galaxies/second/core with good scaling properties.