The galaxy rotation curves in the $f(R,T)$ modified gravity formalism

TL;DR

This paper explores how the $f(R,T)$ modified gravity theory can explain flat galaxy rotation curves, showing that non-minimal coupling models can account for these observations without dark matter.

Contribution

It introduces and analyzes $f(R,T)$ gravity models, demonstrating that non-minimal coupling models can produce flat galaxy rotation curves, addressing a key astrophysical challenge.

Findings

Non-minimal coupling models can produce flat rotation curves.

Separable models cannot account for flat rotation curves.

Supports modified gravity as an alternative to dark matter.

Abstract

Astronomical data have shown that the galaxy rotation curves are mostly flat in the far distance of the galactic cores, which reveals the insufficiency of our knowledges about how gravity works in these regimes. In this paper we introduce a resolution of this issue from the $f(R,T)$ modified gravity formalism perspective. By investigating two classes of models with separable (minimal coupling model) and inseparable (non-minimal coupling model) parts of the Ricci scalar $R$ and trace of the energy-momentum tensor $T$, we find that only in the latter models it is possible to attain flat galaxy rotation curves.