A new method for model-agnostic gravity with weak lensing and galaxy clusteringConfirmed

by Danielle Leonard (Newcastle University)

Monday Apr 7, 2025, 1:00 p.m. → 2:30 p.m. America/Toronto

PI/3-394 - Skyroom (Perimeter Institute for Theoretical Physics)

The standard method for testing gravity in a model-agnostic way with weak lensing and galaxy clustering involves throwing away huge portions of our data sets to deal with nonlinear modelling uncertainties, leading to wildly less informative constraints. In this talk, I will introduce a novel alternative method for model-agnostic constraints on cosmological gravitational behaviour, which solves this problem. In a simulated analysis, our method offers considerably tighter constraints on model-agnostic cosmological modified gravity parameters.  It also breaks key degeneracies in the gravitational + cosmological parameter space using weak lensing and galaxy clustering alone, which is not possible in the standard analysis method. Our method is a promising option for cosmological tests of gravity with ongoing and upcoming surveys Euclid and Rubin Observatory's LSST.