A two measure model of dark energy and dark matter

Abstract

In this work we construct a unified model of dark energy and dark matter. This is donewith the following three elements: a gravitating scalar field, ϕ with a non-conventional kinetic term, as in the string theory tachyon; an arbitrary potential, V(ϕ);two measures — a metric measure ((−g)1/2) and a non-metric measure(Φ). The model has two interesting features: (i) For potentials which are unstable and would give rise to tachyonic scalar field, this modelcan stabilize the scalar field. (ii) The form of the dark energy and dark matter that results from this modelis fairly insensitive to the exact form of the scalar field potential.