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

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.043520· OSTI ID:21409274

Changjun, Gao ^[1]; Kunz, Martin ^[2]; Liddle, Andrew R; Parkinson, David ^[2]

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1. National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China)
2. Astronomy Centre, University of Sussex, Brighton BN1 9QH (United Kingdom)

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.

• OSTI ID: 21409274
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 4; Other Information: DOI: 10.1103/PhysRevD.81.043520; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPARATIVE EVALUATIONS
ENERGY-MOMENTUM TENSOR
EQUATIONS OF MOTION
EQUATIONS OF STATE
LAGRANGIAN FUNCTION
NONLUMINOUS MATTER
SCALAR FIELDS
VELOCITY
DIFFERENTIAL EQUATIONS
EQUATIONS
EVALUATION
FUNCTIONS
MATTER
PARTIAL DIFFERENTIAL EQUATIONS
TENSORS