The two-loop bispectrum in the effective theory of large-scale structure

TL;DR

This paper advances the theoretical modeling of the large-scale structure bispectrum by including two-loop corrections in the effective field theory framework, improving agreement with simulations.

Contribution

It derives an analytic two-loop bispectrum correction in EFTofLSS and demonstrates extended accuracy in comparison with N-body simulations.

Findings

Two-loop corrections improve the bispectrum modeling accuracy.

UV-sensitivity is absorbed by existing EFT operators.

Agreement with simulations extends to higher wavenumbers.

Abstract

We study the bispectrum of large-scale structure in the EFTofLSS including corrections up to two-loop. We derive an analytic result for the double-hard limit of the two-loop correction, and show that the UV-sensitivity can be absorbed by the same four EFT operators that renormalize the one-loop bispectrum. For the single-hard region, we employ a simplified treatment, introducing one extra EFT parameter. We compare our results to N-body simulations, and show that going from one- to two-loop extends the wavenumber range with percent-level agreement from $k \simeq 0.08$ to $0.15~h/\mathrm{Mpc}$.