The halo bias inside cosmic voids

TL;DR

This paper investigates the scale-dependent bias and mass function of dark matter halos within cosmic voids using simulations, providing a new theoretical model with high accuracy to enhance cosmological analyses.

Contribution

It introduces the first scale-dependent model of halo bias and mass function inside cosmic voids, validated against simulations with 1% accuracy.

Findings

Halo bias inside voids is scale-dependent along the void profile.

Theoretical model accurately predicts halo bias within 1%.

Results improve understanding of halo formation in cosmic voids.

Abstract

The bias of dark matter halos and galaxies is a crucial quantity in many cosmological analyses. In this work, using large cosmological simulations, we explore the halo mass function and halo bias within cosmic voids. For the first time to date, we show that they are scale-dependent along the void profile, and provide a predictive theoretical model of both the halo mass function and halo bias inside voids, recovering for the latter and 1% accuracy against simulated data. These findings may help shed light on the dynamics of halo formation within voids and improve the analysis of several void statistics from ongoing and upcoming galaxy surveys.