# Light scalar dark matter coupled to a trace of energy-momentum tensor

## TL;DR

This paper investigates a light scalar dark matter model with suppressed interactions via the energy-momentum tensor, analyzing its evolution and constraints from early universe physics.

## Contribution

It introduces a novel coupling of scalar dark matter to the energy-momentum tensor and explores its cosmological implications and bounds.

## Key findings

- Constraints on model parameters from Big Bang Nucleosynthesis.
- Effects on the evolution of the scalar dark matter field.
- Bounds on the coupling strength from fundamental constant variations.

## Abstract

We consider dark matter represented by the light scalar field whose coupling to the ordinary matter is extremely suppressed. We assume that this interaction can be described as the coupling of the square of the field to the energy-momentum tensor. We study the effect of this interaction on the evolution of dark matter scalar, as well as bounds on the model parameters that come from the variation of fundamental constants at the BBN.