# Galactic dynamics and long-range quantum gravity

## TL;DR

This paper investigates the hypothesis that long-range quantum gravity effects could explain galactic phenomena typically attributed to dark matter, proposing a new IR scale and linking it to observed galactic acceleration patterns.

## Contribution

It introduces a mechanism where quantum gravity effects generate an IR scale and excitations that mimic dark matter effects, providing a novel explanation consistent with observations and MOND.

## Key findings

- Long-range quantum gravity effects can produce galactic acceleration profiles.
- The IR scale $r_0$ is linked to the breaking of de Sitter symmetry by baryonic matter.
- The results align with observational data and MOND phenomenology.

## Abstract

We explore in a systematic way the possibility that long-range quantum gravity effects could play a role at galactic scales and could be responsible for the phenomenology commonly attributed to dark matter. We argue that the presence of baryonic matter breaks the scale symmetry of the de Sitter (dS) spacetime generating an IR scale $r_0$, corresponding to the scale at which the typical dark matter effects we observe in galaxies arise. It also generates a huge number of bosonic excitations with wavelength larger than the size of the cosmological horizon and in thermal equilibrium with dS spacetime. We show that for $r\gtrsim r_0$ these excitations produce a new component for the radial acceleration of stars in galaxies which leads to the result found by McGaugh {\sl et al.} by fitting a large amount of observational data and with the MOND theory. We also propose a generalized thermal equivalence principle and use it to give another independent derivation of our result. Finally, we show that our result can be also derived as the weak field limit of Einstein's general relativity sourced by an anisotropic fluid.