Damping of the baryon acoustic oscillations in the matter power spectrum as a probe of the growth factor

TL;DR

This paper develops an analytic model for the damping of baryon acoustic oscillations in the matter power spectrum caused by quasi-nonlinear clustering, linking it to the growth factor, and explores its use for constraining cosmological growth.

Contribution

It introduces a new fitting formula based on third order perturbation theory that relates BAO damping to the growth factor, enhancing the understanding of nonlinear effects in cosmology.

Findings

The damping of BAO is closely related to the growth factor.

A new analytic fitting formula for BAO damping is proposed.

Feasibility of constraining the growth factor via BAO damping is discussed.

Abstract

We investigate the damping of the baryon acoustic oscillations (BAO) signature in the matter power spectrum due to the quasi-nonlinear clustering of density perturbations. On the basis of the third order perturbation theory, we construct a fitting formula of the damping in an analytic way. This demonstrates that the damping is closely related with the growth factor and the amplitude of the matter power spectrum. Then, we investigate the feasibility of constraining the growth factor through a measurement of the damping of the BAO signature. An extension of our formula including higher order corrections of density perturbations is also discussed.