Unified Dark Energy-Dark Matter model with Inverse Quintessence

TL;DR

This paper proposes a unified model of dark energy and dark matter using a scalar field with non-standard kinetic terms, leading to an inverse quintessence scenario where vacuum energy starts at zero and increases over time.

Contribution

It introduces a novel scalar field model with non-conventional kinetic terms that naturally produces an inverse quintessence evolution of the universe.

Findings

Dark energy vanishes in the early universe and grows with time.

The model achieves a unified description of dark energy and dark matter.

Inverse quintessence scenario is realized through ghost-type kinetic terms.

Abstract

We consider a model where both dark energy and dark matter originate from the coupling of a scalar field with a non-conventional kinetic term to, both, a metric measure and a non-metric measure. An interacting dark energy/dark matter scenario can be obtained by introducing an additional scalar that can produce non constant vacuum energy and associated variations in dark matter. The phenomenology is most interesting when the kinetic term of the additional scalar field is ghost-type, since in this case the dark energy vanishes in the early universe and then grows with time. This constitutes an "inverse quintessence scenario", where the universe starts from a zero vacuum energy density state, instead of approaching it in the future.