Probing dark energy with tomographic weak-lensing aperture mass statistics
Nicolas Martinet, Joachim Harnois-Déraps, Eric Jullo, Peter Schneider
Abstract
We forecast and optimize the cosmological power of various weak-lensing aperture mass ( M ap ) map statistics for future cosmic shear surveys, including peaks, voids, and the full distribution of pixels (1D M ap ). These alternative methods probe the non-Gaussian regime of the matter distribution, adding complementary cosmological information to the classical two-point estimators. Based on the SLICS and cosmo-SLICS N -body simulations, we build Euclid -like mocks to explore the S 8 − Ω m − w 0 parameter space. We develop a new tomographic formalism that exploits the cross-information between redshift slices (cross- M ap ) in addition to the information from individual slices (auto- M ap ) probed in the standard approach. Our auto- M ap forecast precision is in good agreement with the recent literature on weak-lensing peak statistics and is improved by ∼50% when including cross- M ap . It is further boosted by the use of 1D M ap that outperforms all other estimators, including the shear two-point correlation function ( γ -2PCF). When considering all tomographic terms, our uncertainty range on the structure growth parameter S 8 is enhanced by ∼45% (almost twice better) when combining 1D M ap and the γ -2PCF compared to the γ -2PCF alone. We additionally measure the first combined forecasts on the dark energy equation of state w 0 , finding a factor of three reduction in the statistical error compared to the γ -2PCF alone. This demonstrates that the complementary cosmological information explored by non-Gaussian M ap map statistics not only offers the potential to improve the constraints on the recent σ 8 –Ω m tension, but also constitutes an avenue to understanding the accelerated expansion of our Universe.