# Cosmological inviability of $f(R,T)$ gravity

## TL;DR

This paper critically examines $f(R,T)$ gravity theories, highlighting their difficulties in producing realistic cosmological models and questioning their viability as alternatives to General Relativity.

## Contribution

The study provides a detailed analysis of the challenges faced by $f(R,T)$ gravity in explaining viable cosmology, offering a critical perspective on its theoretical consistency.

## Key findings

- $f(R,T)$ theories struggle to produce realistic cosmological solutions.
- The analysis reveals fundamental issues in the matter-geometry coupling.
- Results challenge the viability of $f(R,T)$ as an alternative gravity model.

## Abstract

Among many alternative gravitational theories to General Relativity (GR), $f(R,T)$ gravity (where $R$ is the Ricci scalar and $T$ the trace of the energy-momentum tensor) has been widely studied recently. By adding a matter contribution to the gravitational Lagrangian, $f(R,T)$ theories have become an interesting extension to GR displaying a broad phenomenology in astrophysics and cosmology. In this paper, we discuss however the difficulties appearing in explaining a viable and realistic cosmology within the $f(R,T)$ class of theories. Our results challenge the viability of $f(R,T)$ as an alternative modification of gravity.