The self-similarity of weak lensing peaks

Abstract

We study the statistics of weak lensing convergence peaks, such as their abundance and twopoint correlation function (2PCF), for a wide range of cosmological parameters Ω m and σ 8 within the standard ΛCDM paradigm, focusing on intermediate-height peaks with signal-tonoise ratio (SNR) of 1.5 to 3.5. We find that the cosmology dependence of the peak abundance can be described by a one-parameter fitting formula that is accurate to within ∼ 3%. The peak 2PCFs are shown to feature a self-similar behaviour: if the peak separation is rescaled by the mean inter-peak distance, catalogues with different minimum peak SNR values have identical clustering, which suggests that the peak abundance and clustering are closely interconnected. A simple fitting model for the rescaled 2PCF is given, which together with the peak abundance model above can predict peak 2PCFs with an accuracy better than ∼ 5%. The abundance and 2PCFs for intermediate peaks have very different dependencies on Ω m and σ 8 , implying that their combination can be used to break the degeneracy between these two parameters.

Optimal void finders in weak lensing maps

“…This will be especially interesting in the context of the m -σ 8 degeneracy. Both galaxy voids and WL peaks have been shown to be able to help break this parameter degeneracy (Dietrich & Hartlap 2010;Davies et al 2019a;Nadathur et al 2019), and WL voids may offer another promising avenue to do so.…”

“…This approach guarantees that void identification is not biased away from large voids due to boundary effects. For more details on our projection method, see appendix A of Davies et al (2019a).…”

“…This complementary information contained in the abundance of WL peaks has been exploited to improve cosmological constraints on CDM parameters (Shan et al 2012;Van Waerbeke et al 2013;Shan et al 2014;Liu et al 2015), modified gravity (Cardone et al 2013;Higuchi & Shirasaki 2016;Liu et al 2016;Shirasaki et al 2017;Peel et al 2018), dark energy (Giocoli et al 2018), and the sum of neutrino masses (Li et al 2019). Additional WL peak statistics, such as the two-point correlation function, have also been shown to be sensitive to the CDM parameters (Davies, Cautun & Li 2019a).…”

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;…”

Novel Probes Project: Tests of gravity on astrophysical scales

“…Hence, cluster abundance is also expected to be useful to constrain this type of model. Davies, Cautun, and Li (2019) used weak-lensing peaks as a proxy of massive dark matter halos and found a strong constraining potential on the nDGP model. Quantitative constraints do not yet exist for other screening models such as symmetron and K-mouflage, although modifications to spherical collapse and hence the halo mass function have been explored (Davis, Li et al, 2012;Taddei, 2013;Brax and Valageas, 2014a;Taddei, Catena, and Pietroni, 2014;Brax, Rizzo, and Valageas, 2015).…”