Galactic dark matter effects from purely geometrical aspects of General Relativity

TL;DR

This paper explores how purely geometrical aspects of General Relativity can explain galaxy rotation curves traditionally attributed to dark matter, proposing a potential geometric origin for dark matter effects.

Contribution

It introduces a new limit called strong gravitomagnetism within General Relativity that can account for flat galaxy rotation profiles without dark matter.

Findings

Strong gravitomagnetism can produce flat velocity profiles.

General Relativity corrections can mimic dark matter effects.

A geometric origin for some dark matter phenomena is proposed.

Abstract

We study disc galaxies in the framework of General Relativity to focus on the possibility that, even in the low energy limit, there are relevant corrections with respect to the purely Newtonian approach. Our analysis encompasses the model both considering a low energy expansion and exact solutions, making it clear the connection between these different approaches. In particular, we focus on two different limits: the well known gravitomagnetic analogy and a new limit, called strong gravitomagnetism, which has corrections in c of the same order as the Newtonian terms. We show that these two limits of the general class of solution can account for the observed flat velocity profile, contrary to what happens using Newtonian models, where a dark matter contribution is required. Hence, we suggest a geometrical origin for a certain amount of dark matter effects.