Posterior samples of source galaxies in strong gravitational lenses with score-based priors by Alexandre Adam et al. on Wednesday 30 November

Inferring accurate posteriors for high-dimensional representations of the

brightness of gravitationally-lensed sources is a major challenge, in part due

to the difficulties of accurately quantifying the priors. Here, we report the

use of a score-based model to encode the prior for the inference of undistorted

images of background galaxies. This model is trained on a set of

high-resolution images of undistorted galaxies. By adding the likelihood score

to the prior score and using a reverse-time stochastic differential equation

solver, we obtain samples from the posterior. Our method produces independent

posterior samples and models the data almost down to the noise level. We show

how the balance between the likelihood and the prior meet our expectations in

an experiment with out-of-distribution data.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.03812v2