# BE-HaPPY: Bias Emulator for Halo Power Spectrum including massive neutrinos

## TL;DR

This paper introduces BE-HaPPY, a fast and accurate halo bias emulator for cosmologies with massive neutrinos, validated against N-body simulations and suitable for next-generation large-scale structure surveys.

## Contribution

The paper develops BE-HaPPY, a halo bias emulator calibrated on simulations, providing precise bias predictions for cosmologies with massive neutrinos, compatible with MCMC cosmological inference.

## Key findings

- BE-HaPPY achieves sub-percent accuracy on relevant scales.
- The emulator is fast enough for MCMC analyses.
- It provides prescriptions for halo bias in massive neutrino cosmologies.

## Abstract

We study the clustering properties of dark matter halos in real- and redshift-space in cosmologies with massless and massive neutrinos through a large set of state-of-the-art N-body simulations. We provide quick and easy-to-use prescriptions for the halo bias on linear and mildly non-linear scales, both in real and redshift space, which are valid also for massive neutrinos cosmologies. Finally we present a halo bias emulator,$\textbf{BE-HaPPY}$, calibrated on the N-body simulations, which is fast enough to be used in the standard Markov Chain Monte Carlo approach to cosmological inference. For a fiducial standard $\Lambda$CDM cosmology $\textbf{BE-HaPPY}$ provides percent or sub-percent accuracy on the scales of interest (linear and well into the mildly non-linear regime), meeting therefore for the halo-bias the accuracy requirements for the analysis of next-generation large--scale structure surveys.