Testing for a Super-Acceleration Phase of the Universe

Abstract

We propose a method to probe the phenomenological nature of dark energy which makes no assumptions about the evolution of its energy density. We exemplify this method with a test for a super-acceleration phase of the universe i.e., a phase when the dark energy density grows as the universe expands. We show how such a phase can be detected by combining SNIa (SNAP-like) and CMB (Planck) data without making any assumptions about the evolution of the dark energy equation of state, or about the value of the matter density parameter.

Comments: Matches version accepted for publication in PRD. Added discussion of the effect of the calibration parameter on detecting super-acceleration. 8 pages and 4 figures