A cosmological dust model with extended f(chi) gravity

TL;DR

This paper develops a relativistic gravity model incorporating a fundamental acceleration constant, enabling explanations of cosmic expansion without dark matter or dark energy, and connecting MOND-like behavior with cosmological dynamics.

Contribution

It introduces a new extended f(chi) gravity model that unifies MOND-like non-relativistic limits with a relativistic framework for cosmology.

Findings

The model reproduces galaxy rotation curves without dark matter.

It explains the universe's expansion using a pure metric approach.

The theory aligns with observed large-scale cosmic behavior.

Abstract

Introducing a fundamental constant of nature with dimensions of acceleration into the theory of gravity makes it possible to extend gravity in a very consistent manner. At the non-relativistic level a MOND-like theory with a modification in the force sector is obtained, which is the limit of a very general metric relativistic theory of gravity. Since the mass and length scales involved in the dynamics of the whole universe require small accelerations of the order of Milgrom's acceleration constant a_0, it turns out that the relativistic theory of gravity can be used to explain the expansion of the universe. In this work it is explained how to use that relativistic theory of gravity in such a way that the overall large-scale dynamics of the universe can be treated in a pure metric approach without the need to introduce dark matter and/or dark energy components.