Cosmic acceleration from coupling of baryonic and dark matter components: Analysis and diagnostics

TL;DR

This paper explores how coupling between baryonic and dark matter can cause late-time cosmic acceleration without extra degrees of freedom, using observational data and diagnostics to analyze model behavior.

Contribution

It introduces a coupling-based model for cosmic acceleration, analyzing its consistency with data and distinctive future behavior, without relying on additional fields.

Findings

Models are consistent with Hubble, supernova, and BAO data.

Distinctive future phantom behavior identified.

Coupling induces acceleration without extra degrees of freedom.

Abstract

In this paper, we examine a scenario in which late-time cosmic acceleration might arise due to the coupling between baryonic matter and dark matter without the presence of extra degrees of freedom. In this case, one can obtain late-time acceleration in Jordan frame and not in Einstein frame. We consider two different forms of parametrization of the coupling function, and put constraints on the model parameters by using an integrated datasets of Hubble parameter, Type Ia supernova and baryon acoustic oscillations. The models under consideration are consistent with the observations. In addition, we perform the statefinder and $Om$ diagnostics, and show that the models exhibit a distinctive behavior due to the phantom characteristic in future which is a generic feature of the underlying scenario.