Simultaneous modelling of matter power spectrum and bispectrum in the presence of baryons

TL;DR

This paper shows that baryonification algorithms can accurately model the effects of baryons on both the matter power spectrum and bispectrum in cosmological simulations, up to certain scales and redshifts.

Contribution

The authors develop and validate a baryonification method that jointly fits baryonic effects on power spectrum and bispectrum, improving modeling of baryonic physics in cosmological analyses.

Findings

Achieves 1% accuracy for power spectrum up to k<5 h/Mpc

Models equilateral and squeezed bispectra with ~3% accuracy

Supports physical assumptions of baryonification for cosmological applications

Abstract

We demonstrate that baryonification algorithms, which displace particles in gravity-only simulations according to physically-motivated prescriptions, can simultaneously capture the impact of baryonic physics on the 2 and 3-point statistics of matter. Specifically, we show that our implementation of a baryonification algorithm jointly fits the changes induced by baryons on the power spectrum and equilateral bispectrum on scales up to k < 5 h/Mpc and redshifts z<2, as measured in six different cosmological hydrodynamical simulations. The accuracy of our fits are typically 1% for the power spectrum, and for the equilateral and squeezed bispectra, which somewhat degrades to 3% for simulations with extreme feedback prescriptions. Our results support the physical assumptions underlying baryonification approaches, and encourage their use in interpreting weak gravitational lensing and other cosmological observables.