Non-Gaussian Minkowski functionals & extrema counts in redshift space

TL;DR

This paper develops a formalism to analyze non-Gaussian geometric and topological statistics of cosmic fields in redshift space, accounting for peculiar velocities, to improve parameter estimation in large-scale structure surveys.

Contribution

It introduces a Gram-Charlier expansion approach for anisotropic fields in redshift space and applies it to Minkowski functionals and extrema counts, enhancing analysis of cosmic structures.

Findings

Quantifies non-Gaussian redshift distortion effects on geometric probes

Predicts evolution of Minkowski functionals using gravitational perturbation theory

Estimates parameters sigma(z) and beta from upcoming survey data

Abstract

In the context of upcoming large-scale structure surveys such as Euclid, it is of prime importance to quantify the effect of peculiar velocities on geometric probes. Hence the formalism to compute in redshift space the geometrical and topological one-point statistics of mildly non-Gaussian 2D and 3D cosmic fields is developed. Leveraging the partial isotropy of the target statistics, the Gram-Charlier expansion of the joint probability distribution of the field and its derivatives is reformulated in terms of the corresponding anisotropic variables. In particular, the cosmic non-linear evolution of the Minkowski functionals, together with the statistics of extrema are investigated in turn for 3D catalogues and 2D slabs. The amplitude of the non-Gaussian redshift distortion correction is estimated for these geometric probes. In 3D, gravitational perturbation theory is implemented in redshift space to predict the cosmic evolution of all relevant Gram-Charlier coefficients. Applications to the estimation of the cosmic parameters sigma(z) and beta=f/b1 from upcoming surveys is discussed. Such statistics are of interest for anisotropic fields beyond cosmology.