An analytic implementation of the IR-resummation for the BAO peak

TL;DR

This paper presents an analytic, efficient, and accurate method for IR-resummation of BAO features in large-scale structure, improving computational speed and precision for cosmological data analysis.

Contribution

An analytic implementation of IR-resummation for BAO, enabling faster and more accurate predictions without numerical integration, applicable to higher loop orders.

Findings

Achieves better than 0.2% accuracy compared to numerical methods

Reduces computation time by approximately six times

Demonstrates generalizability to higher loop calculations

Abstract

We develop an analytic method for implementing the IR-resummation of arXiv:1404.5954, which allows one to correctly and consistently describe the imprint of baryon acoustic oscillations (BAO) on statistical observables in large-scale structure. We show that the final IR-resummed correlation function can be computed analytically without relying on numerical integration, thus allowing for an efficient and accurate use of these predictions on real data in cosmological parameter fitting. In this work we focus on the one-loop correlation function and the BAO peak. We show that, compared with the standard numerical integration method of IR-resummation, the new method is accurate to better than 0.2 %, and is quite easily improvable. We also give an approximate resummation scheme which is based on using the linear displacements of a fixed fiducial cosmology, which when combined with the method described above, is about six times faster than the standard numerical integration. Finally, we show that this analytic method is generalizable to higher loop computations.