Weak lensing minima and peaks: Cosmological constraints and the impact of baryons

Abstract

We present a novel statistic to extract cosmological information in weak lensing data: the lensing minima. We also investigate the effect of baryons on cosmological constraints from peak and minimum counts. Using the MassiveNuS simulations, we find that lensing minima are sensitive to non-Gaussian cosmological information and are complementary to the lensing power spectrum and peak counts. For an LSST-like survey, we obtain $95{{\ \rm per\ cent}}$ credible intervals from a combination of lensing minima and peaks that are significantly stronger than from the power spectrum alone, by $44{{\ \rm per\ cent}}$, $11{{\ \rm per\ cent}}$, and $63{{\ \rm per\ cent}}$ for the neutrino mass sum ∑mν, matter density Ωm, and amplitude of fluctuation As, respectively. We explore the effect of baryonic processes on lensing minima and peaks using the hydrodynamical simulations BAHAMAS and Osato15. We find that ignoring baryonic effects would lead to strong (≈4σ) biases in inferences from peak counts, but negligible (≈0.5σ) for minimum counts, suggesting lensing minima are a potentially more robust tool against baryonic effects. Finally, we demonstrate that the biases can in principle be mitigated without significantly degrading cosmological constraints when we model and marginalize the baryonic effects.

Optimal void finders in weak lensing maps

“…These panels illustrate that the WL minima are slightly different from the typical WL void definition used in this work, since they have no size or radius, which has the advantage of simplicity. In later sections, we will discuss the abundance of WL minima as a function of their amplitude, rather than as a function of their size, and the abundance of WL minima has been shown to provide complementary cosmological information to the WL peak abundance (Coulton et al 2020). We also discuss, for the first time, the potential for the radial lensing profiles of WL minima to be used in a cosmological analysis.…”

“…The WL bispectrum, which is sensitive to non-Gaussianity by definition, has been shown to be a useful statistic for future surveys (Cooray & Hu 2001;Rizzato et al 2019;Munshi & McEwen 2020), and can be used to improve parameter constraints, such as neutrino masses (Coulton et al 2019). And finally, WL minima, local minima in the convergence field, are less sensitive to baryonic effects, and offer certain advantages over WL peaks (Coulton et al 2020). Every such novel statistic offers its own unique advantages, which makes the study of novel statistics crucial.…”

Probing dark energy with tomographic weak-lensing aperture mass statistics

“…Two-point statistics fail to capture this non-Gaussian information and thus yield an incomplete description of the matter distribution at low redshift. To close this gap, the community has recently started to explore non-Gaussian cosmic shear estimators: for example weak-lensing peaks (e.g., Kruse & Schneider 1999, 2000Dietrich & Hartlap 2010;Kratochvil et al 2010;Fan et al 2010;Yang et al 2011;Maturi et al 2011;Hamana et al 2012;Hilbert et al 2012;Marian et al 2012Marian et al , 2013Shan et al 2014Shan et al , 2018Lin & Kilbinger 2015;Martinet et al 2015Martinet et al , 2018Liu et al 2015a,b;Kacprzak et al 2016;Petri et al 2016;Zorrilla Matilla et al 2016;Giocoli et al 2018;Peel et al 2018;Davies et al 2019;Fong et al 2019;Li et al 2019;Weiss et al 2019;Yuan et al 2019;Coulton et al 2020;Ajani et al 2020;Zürcher et al 2021), Minkowski functionals (e.g., Kratochvil et al 2012;Petri et al 2015;Vicinanza et al 2019;Parroni et al 2020;Zürcher et al 2021), higher-order moments (e.g., Van Waerbeke et al 2013;Petri et al 2015;Peel et al 2018;Vicinanza et al 2018;…”

“…Other interesting M ap map-sampling methods exist beside peaks: for example voids (e.g., Gruen et al 2016;Coulton et al 2020) and the full distribution of pixels, also known as the lensing probability distribution function (lensing PDF, e.g., Patton et al 2017;Shirasaki et al 2019;Liu & Madhavacheril 2019). Because they probe more massive structures, peaks are less sensitive to noise and are likely better for studying cosmological parameters sensitive to matter (Ω m , σ 8 ) and the sum of neutrino mass (Coulton et al 2020). Voids, however, could offer a better sensitivity to dark energy.…”

“…Indeed, while routinely used in γ-2PCF analyses, tomography has rarely been applied in mass map cosmological analyses (e.g., Yang et al 2011;Martinet et al 2015;Petri et al 2016;Li et al 2019;Coulton et al 2020;Ajani et al 2020;Zürcher et al 2021), less so with a realistic redshift distribution (e.g., Martinet et al 2015;Petri et al 2016;Zürcher et al 2021). One caveat of the current mass map tomography is that it only probes the information from individual redshift slices.…”