Extended LCDM: generalized non-minimal coupling for dark matter fluids

TL;DR

This paper proposes a model where dark matter non-minimally couples with gravity at galactic scales, potentially explaining gravitational dynamics without hidden couplings or abandoning dark matter, and links to phenomena like Bose-Einstein condensation.

Contribution

It introduces a generalized non-minimal coupling framework for dark matter and gravity, offering a geometric approach to galactic dynamics that connects to dark matter phenomenology.

Findings

Model predicts modified gravitational dynamics at galactic scales.

Non-minimal coupling could originate from Bose-Einstein condensation mechanisms.

Provides a geometric interpretation of dark matter interactions.

Abstract

In this paper we discuss a class of models that address the issue of explaining the gravitational dynamics at the galactic scale starting from a geometric point of view. Instead of claiming the existence of some hidden coupling between dark matter and baryons, or abandoning the existence of dark matter itself, we consider the possibility that dark matter and gravity have some non trivial interaction able to modify the dynamics at astrophysical scales. This interaction is implemented assuming that dark matter gets non--minimally coupled with gravity at suitably small scales and late times. After showing the predictions of the model in the Newtonian limit we also discuss the possible origin of it non-minimal coupling. This investigation seems to suggest that phenomenological mechanisms envisaged for the dark matter dynamics, such as the Bose--Einstein condensation of dark matter halos, could be connected to this class of models.