Work

Analytic Gaussian covariance matrices for galaxy N -point correlation functions

Year: 2022

Type: article

Abstract: We derive analytic covariance matrices for the $N$-point correlation functions (NPCFs) of galaxies in the Gaussian limit. Our results are given for arbitrary $N$ and projected onto the isotropic basis functions given by spherical harmonics and Wigner $3j$ symbols. A numerical implementation of the 4PCF covariance is compared to the sample covariance obtained from a set of lognormal simulations, Quijote dark matter halo catalogues, and MultiDark-Patchy galaxy mocks, with the latter including realistic survey geometry. The analytic formalism gives reasonable predictions for the covariances estimated from mock simulations with a periodic-box geometry. Furthermore, fitting for an effective volume and number density by maximizing a likelihood based on Kullback-Leibler divergence is shown to partially compensate for the effects of a nonuniform window function. Our result is recently shown to facilitate NPCF analysis on a realistic survey data.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/physrevd.106.043515

Authors: Jiamin Hou, Robert N. Cahn, Oliver H. E. Philcox, Zachary Slepian

Institutions: University of Florida, Lawrence Berkeley National Laboratory, Princeton University, Institute for Advanced Study

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze