Minimal metagravity vs. dark matter and/or dark energy

TL;DR

This paper explores how minimal metagravity, which breaks general covariance but keeps unimodular invariance, can explain the universe's accelerated expansion and dark matter/energy phenomena through a massive scalar graviton.

Contribution

It introduces a minimal metagravity model with a massive scalar graviton and analyzes its potential to replicate the standard LCDM cosmology.

Findings

The modified Friedmann equation is derived within the minimal metagravity framework.

The scalar graviton can act as dark matter or dark energy.

Discussion on the model's ability to emulate LCDM cosmology.

Abstract

The minimal metagravity theory, explicitly violating the general covariance but preserving the unimodular one, is applied to study the evolution of the isotropic homogeneous Universe. The massive scalar graviton, contained in the theory in addition to the massless tensor one, is treated as a source of the dark matter and/or dark energy. The modified Friedmann equation for the scale factor of the Universe is derived. The question wether the minimal metagravity can emulate the LCDM concordance model, valid in General Relativity, is discussed.