Nonminimally coupled Dark Matter in Clusters of Galaxies: a fully comprehensive analysis

TL;DR

This paper investigates how non-minimal disformal couplings between dark matter and gravity influence galaxy cluster dynamics, using lensing data to constrain the coupling length and find it consistent with general relativity.

Contribution

It provides a comprehensive analysis of all disformal coupling scenarios in galaxy clusters, expanding previous work and constraining the coupling length with observational data.

Findings

Coupling length is typically very small, consistent with general relativity.

Upper limit on coupling length is around 100 kpc at 1 sigma.

Analysis uses multiple statistical approaches with lensing data.

Abstract

In this study, we explore how a non-minimal coupling between dark matter and gravity can affect the behavior of dark matter in galaxy clusters. We have considered the case of a disformal coupling, which leads to a modification of the Poisson equation. Building on an earlier work, we expand the analysis considering all possible disformal coupling scenarios and employing various dark matter density profiles. In doing so, we aim to constrain the key parameter in our model, the characteristic coupling length. To achieve this, we analyze data from a combination of strong and weak lensing using three statistical approaches: a single cluster fitting procedure, a joint analysis, and one with stacked profiles. Our findings show that the coupling length is typically very small, thus being fully consistent with general relativity, although with an upper limit at $1\sigma$ which is of the order of $100$ kpc.