Joint analysis of anisotropic power spectrum, bispectrum and trispectrum: application to N-body simulations

Abstract

We perform for the first time a joint analysis of the monopole and quadrupoles for power spectrum, bispectrum and integrated trispectrum (i-trispectrum) from the redshift space matter field in N-body simulations. With a full Markov Chain Monte Carlo exploration of the posterior distribution, we quantify the constraints on cosmological parameters for an object density of n p = 5 × 10-4 (h Mpc-1)3, redshift z = 0.5, and a covariance corresponding to a survey volume of V survey = 25 (h -1Gpc)3, a set up which is representative of forthcoming galaxy redshift surveys. We demonstrate the complementarity of the bispectrum and i-trispectrum in constraining key cosmological parameters. In particular, compared to the state-of-the-art power spectrum (monopole plus quadrupole) and bispectrum (monopole) analyses, we find 1D 68% credible regions smaller by a factor of (72%,78%,72%,47%,46%) for the parameters (f,σ8,f nl,α∥,α⊥) respectively. This work motivates the additional effort necessary to include the redshift-space anisotropic signal of higher-order statistics in the analysis and interpretation of ongoing and future galaxy surveys.