paper

Redshift space power spectrum beyond Einstein-de Sitter kernels

arXiv:2012.05077 · doi:10.1088/1475-7516/2021/04/039

Abstract

We develop a framework to compute the redshift space power spectrum (PS), with kernels beyond Einstein-de Sitter (EdS), that can be applied to a wide variety of generalized cosmologies. We build upon a formalism that was recently employed for standard cosmology in Chen, Vlah & White (2020), and utilize an expansion of the density-weighted velocity moment generating function that explicitly separates the magnitude of the -modes and their angle to the line-of-sight direction dependencies. We compute the PS for matter and biased tracers to 1-loop Perturbation Theory (PT) and show that the expansion has a correct infrared and ultraviolet behavior, free of unwanted divergences. We also add Effective Field Theory (EFT) counterterms, necessary to account for small-scale contributions to PT, and employ an IR-resummation prescription to properly model the smearing of the BAO due to large scale bulk flows within Standard-PT. To demonstrate the applicability of our formalism, we apply it on the CDM and the Hu-Sawicki models, and compare our numerical results against the ELEPHANT suite of -body simulations, finding very good agreement up to at for the first three non-vanishing Legendre multipoles of the PS. To our knowledge, the model presented in this work is the most accurate theoretical EFT-PT for modified gravity to date, being the only one that accounts for beyond linear local biasing in redshift-space. Hence, we argue our RSD modeling is a promising tool to construct theoretical templates in order to test deviations from CDM using real data obtained from the next stage of cosmological surveys such as DESI and LSST.

56 pages, 11 figures, version 2 with minor changes

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Redshift space power spectrum beyond Einstein-de Sitter kernels · wovepaper