Testing General Relativity using the Environmental Dependence of Dark Matter Halos

TL;DR

This paper explores how dark matter halo properties vary with environment in modified gravity theories, proposing observational tests to distinguish these from general relativity.

Contribution

It demonstrates the environmental dependence of halo mass estimates in f(R) gravity models using high-resolution simulations, providing a new observational test for GR.

Findings

Strong environmental dependence of lensing and dynamical mass differences in f(R) models

Potential observational signature to test modifications of gravity

Supports using halo environment as a probe for gravity theories

Abstract

In this Letter, we investigate the environmental dependence of dark matter halos in theories that attempt to explain the accelerated expansion of the Universe by modifying general relativity (GR). Using high-resolution N-body simulations in f(R) gravity models which recover GR in dense environments by virtue of the chameleon mechanism, we find a strong environmentally-dependent difference between the lensing mass and dynamical mass estimates of dark matter halos. This environmental dependence of the halo properties can be used as a smoking gun to test GR observationally.