An emulator-based halo model in modified gravity -I. The halo concentration-mass relation and density profile

Abstract

In this series of papers, we present an emulator-based halo model for the non-linear clustering of galaxies in modified gravity cosmologies. In the first paper, we present emulators for the following halo properties: the halo mass function, concentration-mass relation and halo-matter cross-correlation function. The emulators are trained on data extracted from the FORGE and BRIDGE suites of N -body simulations, respectively, for two modified gravity (MG) theories: f ( R ) gravity, and the DGP model, varying three standard cosmological parameters μm0 , H 0 , σ8 , and one MG parameter, either f R0 or r c . Our halo property emulators achieve an accuracy of _ 1 per cent on independent test data sets. We demonstrate that the emulators can be combined with a galaxy-halo connection prescription to accurately predict the g alaxy-g alaxy and galaxy-matter correlation functions using the halo model framework.