Lifting weak lensing degeneracies with a field-based likelihood

ABSTRACT We present a field-based approach to the analysis of cosmic shear data infer jointly cosmological parameters and dark matter distribution. This forward modelling samples initial fluctuations, using physical gravity model link primordial fluctuations non-linear Cosmological are sampled updated consistently through model, varying (1) power spectrum, (2) geometry distance-redshift relationship, (3) growth structure light-cone effects. Our extracts more information from than methods based on two-point statistics. find that this lifts strong degeneracy between density, ?m, fluctuation amplitude, ?8, providing tight constraints these weak lensing alone. In simulated four-bin tomographic experiment we consider, likelihood yields marginal uncertainties ?8 ?m are, respectively, factor 3 5 smaller those spectrum applied same underlying data.