Cosmology with interaction in the dark sector

TL;DR

This paper explores the cosmological implications of a general interacting dark sector model, analyzing observational data to constrain the interaction parameter and examining energy transfer directions.

Contribution

It introduces a coupled scalar field model for interacting dark matter and dark energy with a new parameter and performs a comprehensive statistical analysis with multiple cosmological data sets.

Findings

Energy transfer from dark matter to dark energy is favored, despite being physically forbidden in some cases.

The interaction parameter $psilon$ is constrained by observational data.

The model provides insights into the possible dynamics of the dark sector.

Abstract

Unless some unknown symmetry in Nature prevents or suppresses a non-minimal coupling in the dark sector, the dark energy field may interact with the pressureless component of dark matter. In this paper, we investigate some cosmological consequences of a general model of interacting dark matter-dark energy characterized by a dimensionless parameter $\epsilon$. We derive a coupled scalar field version for this general class of scenarios and carry out a joint statistical analysis involving SNe Ia data ({Legacy} and {Constitution} sets), measurements of baryon acoustic oscillation peak at $z = 0.20$ (2dFGRS) and $z = 0.35$ (SDSS), and measurements of the Hubble evolution $H(z)$. For the specific case of vacuum decay ($w = -1$), we find that, although physically forbidden, a transfer of energy from dark matter to dark energy is favored by the data.