A two measure model of dark energy and dark matter

TL;DR

This paper proposes a unified model of dark energy and dark matter using a scalar field with a non-conventional kinetic term, two measures, and an arbitrary potential, which stabilizes tachyonic fields and yields robust dark sector behaviors.

Contribution

It introduces a novel two-measure framework combining a scalar field and arbitrary potential to unify dark energy and dark matter, stabilizing tachyonic instabilities.

Findings

Model stabilizes tachyonic scalar fields.

Dark energy and dark matter forms are insensitive to potential details.

Provides a unified approach to dark sector modeling.

Abstract

In this work we construct a unified model of dark energy and dark matter. This is done with the following three elements: a gravitating scalar field, phi with a non-conventional kinetic term, as in the string theory tachyon; an arbitrary potential, V(phi); two measures -- a metric measure (sqrt{-g}) and a non-metric measure (Phi). The model has two interesting features: (i) For potentials which are unstable and would give rise to tachyonic scalar field, this model can stabilize the scalar field. (ii) The form of the dark energy and dark matter that results from this model is fairly insensitive to the exact form of the scalar field potential.