Unified dark energy and dark matter from a scalar field different from quintessence

Gao, Changjun, Kunz, Martin, Liddle, Andrew R and Parkinson, David (2010) Unified dark energy and dark matter from a scalar field different from quintessence. Physical Review D, 81 (4). ISSN 1550-7998

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Abstract

We explore unification of dark matter and dark energy in a theory containing a scalar field of non-Lagrangian type, obtained by direct insertion of a kinetic term into the energy-momentum tensor. This scalar is different from quintessence, having an equation of state between -1 and 0 and a zero sound speed in its rest frame. We solve the equations of motion for an exponential potential via a rewriting as an autonomous system, and demonstrate the observational viability of the scenario, for sufficiently small exponential potential parameter lambda, by comparison to a compilation of kinematical cosmological data.

Item Type: Article
Additional Information: Article Number: 043520
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Depositing User: Andrew Liddle
Date Deposited: 06 Feb 2012 19:15
Last Modified: 13 Mar 2017 08:29
URI: http://sro.sussex.ac.uk/id/eprint/19796

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