Probing dark energy with tomographic weak-lensing aperture mass statistics

Abstract

We forecast and optimize the cosmological power of various weak-lensing aperture mass (Map) map statistics for future cosmic shear surveys, including peaks, voids, and the full distribution of pixels (1D Map). 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 S8 − Ωm − w0 parameter space. We develop a new tomographic formalism that exploits the cross-information between redshift slices (cross-Map) in addition to the information from individual slices (auto-Map) probed in the standard approach. Our auto-Map forecast precision is in good agreement with the recent literature on weak-lensing peak statistics and is improved by ∼50% when including cross-Map. It is further boosted by the use of 1D Map 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 S8 is enhanced by ∼45% (almost twice better) when combining 1D Map and the γ-2PCF compared to the γ-2PCF alone. We additionally measure the first combined forecasts on the dark energy equation of state w0, 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 Map map statistics not only offers the potential to improve the constraints on the recent σ8–Ωm tension, but also constitutes an avenue to understanding the accelerated expansion of our Universe.

Impact of baryons in cosmic shear analyses with tomographic aperture mass statistics

“…Consequently, the combination of both probes yields even tighter constraints, as seen in recent applications to observational data (e.g., Martinet et al 2018;Harnois-Déraps et al 2020). With future Stage IV surveys, this combination is also expected to improve not only our measurement of the growth of structure parameter S 8 by a factor of two, but also that of the dark energy equation of state w 0 (Martinet et al 2021) and of the sum of neutrino masses Σm ν (Li et al 2019), by factors of three and two, respectively.…”

“…So far, most analyses have focused on studying the correlation between the shape distortions of pairs of galaxies as a function of their separation: the so-called shear two-point correlation function (γ-2PCF; e.g., Troxel et al 2018;Hikage et al 2019;Asgari et al 2021). However, it is becoming clear that other estimators, and in particular those based on weak-lensing mass maps, outperform the standard γ-2PCF (e.g., Dietrich & Hartlap 2010;Ajani et al 2020;Zürcher et al 2021;Coulton et al 2020;Martinet et al 2021). Indeed, mass maps are highly sensitive to the nonGaussian part of the matter distribution that arises from the nonlinear growth of structures, which contains information that is overlooked by two-point estimators.…”

“…Building on these previous analyses, and exploiting the cosmological analysis pipeline introduced in Martinet et al (2021), we measure for the first time the effect of baryons on the dark matter and dark energy cosmological parameters in a tomographic Stage-IV lensing survey setup. We focus on the particular case of aperture-mass (M ap ; Schneider 1996) maps, which are particularly well suited for cosmological analyses.…”

“…Both effects redistribute the matter in and around DM haloes, but the exact amplitude of the feedback varies between simulations (see Chisari et al 2019, for a recent review on feedback in cosmological hydrodynamical simulations). Extending the simulation suites of Martinet et al (2021) based on the SLICS and the cosmo-SLICS, we construct Euclid-like mocks from the Magneticum hydrodynamical simulation. We measure the impact of baryons on the γ-2PCF, on the lensing peaks, minima, and on the lensing PDF, in the form of a multiplicative baryon bias correction factor.…”

Starletℓ1-norm for weak lensing cosmology

“…Another weak lensing probe of large-scale structure is represented by cosmic voids, namely under-dense regions of the large-scale matter field (Colberg et al 2008;Pisani et al 2019). Local minima of weak lensing convergence maps, namely pixels with values smaller than their eight neighbouring pixels, have been proposed as tracers of the matter distribution voids to infer cosmological parameters, both in a mono-scale setting (Coulton et al 2020;Martinet et al 2021;Davies et al 2020) and in a multi-scale setting (Zürcher et al 2020). More specifically, Coulton et al (2020) found that lensing minima alone are slightly less constraining than the peaks alone and, in agreement with Martinet et al (2021) and Zürcher et al (2020), that the combination of the two statistics produces significantly tighter constraints than the power spectrum.…”