On the IR-Resummation in the EFTofLSS

TL;DR

This paper introduces a simplified IR-resummation method in the EFTofLSS that maintains accuracy in power spectrum predictions and confirms robustness in BAO peak shape modeling, matching simulations up to certain scales.

Contribution

A new simplified IR-resummation formula for EFTofLSS that includes next-to-leading order corrections and preserves key properties of previous methods.

Findings

Resummation formula shares properties with Senatore and Zaldarriaga's approach.

Two-loop calculation matches Dark Sky simulation power spectrum up to k≈0.34 h/Mpc.

Subleading terms minimally affect the BAO peak shape.

Abstract

We propose a simplification for the IR-resummation scheme of Senatore and Zaldarriaga, and also include its next-to-leading order corrections coming from the tree-level three-point function of the long displacement field. First we show that the new simplified formula shares the same properties of the resummation of Senatore and Zaldarriaga. In Fourier space, the IR-resummed power spectrum has no residual wiggles and the two-loop calculation matches the non-linear power spectrum of the Dark Sky simulation at $z=0$ up to $k\simeq0.34\,h\,\text{Mpc}^{-1}$ within cosmic variance. Then, we find that the additional subleading terms (although parametrically infrared-enhanced) modify the leading-order IR-resummed correlation function only in a marginal way, implying that the IR-resummation scheme can robustly predict the shape of the BAO peak.