Exact models with non-minimal interaction between dark matter and (either phantom or quintessence) dark energy

TL;DR

This paper generalizes a method to derive exact FRW solutions with non-minimal dark matter and dark energy interactions, introducing new models, including those crossing the phantom barrier and addressing the coincidence problem.

Contribution

It extends an existing solution-generating method to include non-minimal couplings, providing new exact solutions and models that address the coincidence problem and phantom barrier crossing.

Findings

New flat FRW solutions with non-minimal dark sector coupling.

A model crossing the phantom barrier at late times.

Solutions free from the coincidence problem.

Abstract

A method for deriving Friedmann-Robertson-Walker (FRW) solutions developed in Int. J. Mod. Phys. D{\bf 5}(1996)71-84, is generalized to account for models with non-minimal coupling between the dark energy and the dark matter. New quintessence and phantom (flat) FRW solutions are found. Their physical significance is discussed. Additionally, the aforementioned method is modified so that, "coincidence free" solutions can be readily derived. Besides, we review some aspects of the phantom barrier crossing. In this regard we present a model which is free from the coincidence problem and, at the same time, does the crossing of the phantom barrier $\omega=-1$ at late time. Finally, we give additional comments on the non predictive properties of scalar field cosmological models with or without energy transfer.