An interacting model for the cosmological dark sector

TL;DR

This paper proposes a new interacting dark sector model where dark matter dilution depends on a function related to entropy, and uses observational data to constrain this function.

Contribution

It introduces a novel dark sector interaction model with a thermodynamically motivated function and derives cosmological solutions constrained by data.

Findings

The model's function f(a) is proportional to entropy source.

Viable cosmological solutions are obtained from the model.

Observational data constrains the form of f(a).

Abstract

We discuss a new interacting model for the cosmological dark sector in which the attenuated dilution of cold dark matter scales as $a^{-3}f(a)$, where f(a) is an arbitrary function of the cosmic scale factor $a$. From thermodynamic arguments, we show that f(a) is proportional to entropy source of the particle creation process. In order to investigate the cosmological consequences of this kind of interacting models, we expand f(a) in a power series and viable cosmological solutions are obtained. Finally, we use current observational data to place constraints on the interacting function f(a).