A revised density split statistic model for general filters
Abstract
Context. Studying the statistical properties of the largescale structure in the Universe with weak gravitational lensing is a prime goal of several current and forthcoming galaxy surveys. The power that weak lensing has to constrain cosmological parameters can be enhanced by considering statistics beyond secondorder shear correlation functions or power spectra. One such higherorder probe that has proven successful in observational data is density split statistics (DSS), in which one analyses the mean shear profiles around points that are classified according to their foreground galaxy density.
Aims: In this paper, we generalise the most accurate DSS model to allow for a broad class of angular filter functions used for the classification of the different local density regions. This approach is motivated by earlier findings showing that an optimised filter can provide tighter constraints on model parameters compared to the standard tophat case.
Methods: As in the previous DSS model we built on large deviation theory approaches and approximations thereof to model the matter density probability distribution function, and on perturbative calculations of higherorder moments of the density field. The novel addition relies on the generalisation of these previously employed calculations to allow for general filter functions and is validated on several sets of numerical simulations.
Results: It is shown that the revised model fits the simulation measurements well for many filter choices, with a residual systematic offset that is small compared to the statistical accuracy of current weak lensing surveys. However, by use of a simple calibration method and a Markov chain Monte Carlo analysis, we studied the expected sensitivity of the DSS to cosmological parameters and find unbiased results and constraints comparable to the commonly used twopoint cosmic shear measures. Hence, our DSS model can be used in competitive analyses of current cosmic shear data, while it may need refinements for forthcoming lensing surveys.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 May 2022
 DOI:
 10.1051/00046361/202141628
 arXiv:
 arXiv:2106.13214
 Bibcode:
 2022A&A...661A.137B
 Keywords:

 gravitational lensing: weak;
 largescale structure of Universe;
 methods: statistical;
 galaxies: abundances;
 surveys;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 21 pages, 13 figures