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arXiv · 0912.0949

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

Changjun Gao·Martin Kunz·Andrew R Liddle·David Parkinson
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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.

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Changjun Gao, Martin Kunz, Andrew R Liddle, David Parkinson. 2009-12-05. Unified dark energy and dark matter from a scalar field different from quintessence. https://doi.org/10.1103/physrevd.81.043520

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