Effective Theories of Redshift-Space Galaxy Peculiar Velocities

Fuente: arXiv
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Main Authors: Chen, Shi-Fan, Howlett, Cullan, Lai, Yan, Qin, Fei
Format: Preprint
Published: 2025
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author Chen, Shi-Fan
Howlett, Cullan
Lai, Yan
Qin, Fei
author_facet Chen, Shi-Fan
Howlett, Cullan
Lai, Yan
Qin, Fei
contents We present predictions for redshift-space peculiar velocity statistics in the Lagrangian and Eulerian formulations of the effective field theory (EFT) of large-scale structure. We compute 2-point pairwise velocity statistics up to the second moment at next-to-leading (1-loop) order, showing that they can be modeled together with redshift-space galaxy densities with a consistent set of EFT coefficients. We show that peculiar velocity statistics have a distinct dependence on long-wavelength bulk flows that necessitates a variation on the usual infrared (IR) resummation procedure used to model baryon acoustic oscillations (BAO) in galaxy clustering. This can be implemented recursively in powers of the velocity in both the Lagrangian and Eulerian frameworks. We validate our analytic calculations against fully nonlinear N-body simulations, demonstrating that they can be used to recover the growth rate at better than percent level precision, well beyond the statistical requirements of upcoming peculiar velocity surveys and measurements of the kinetic Sunyaev-Zeldovich (kSZ) effect. As part of this work, we release $\href{https://github.com/sfschen/velocisaurus}{\texttt{velocisaurus}}$, a fast $\texttt{Python}$ code for computing EFT predictions of peculiar velocity statistics.
format Preprint
id arxiv_https___arxiv_org_abs_2508_00066
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Effective Theories of Redshift-Space Galaxy Peculiar Velocities
Chen, Shi-Fan
Howlett, Cullan
Lai, Yan
Qin, Fei
Cosmology and Nongalactic Astrophysics
We present predictions for redshift-space peculiar velocity statistics in the Lagrangian and Eulerian formulations of the effective field theory (EFT) of large-scale structure. We compute 2-point pairwise velocity statistics up to the second moment at next-to-leading (1-loop) order, showing that they can be modeled together with redshift-space galaxy densities with a consistent set of EFT coefficients. We show that peculiar velocity statistics have a distinct dependence on long-wavelength bulk flows that necessitates a variation on the usual infrared (IR) resummation procedure used to model baryon acoustic oscillations (BAO) in galaxy clustering. This can be implemented recursively in powers of the velocity in both the Lagrangian and Eulerian frameworks. We validate our analytic calculations against fully nonlinear N-body simulations, demonstrating that they can be used to recover the growth rate at better than percent level precision, well beyond the statistical requirements of upcoming peculiar velocity surveys and measurements of the kinetic Sunyaev-Zeldovich (kSZ) effect. As part of this work, we release $\href{https://github.com/sfschen/velocisaurus}{\texttt{velocisaurus}}$, a fast $\texttt{Python}$ code for computing EFT predictions of peculiar velocity statistics.
title Effective Theories of Redshift-Space Galaxy Peculiar Velocities
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2508.00066