Scalar field perturbations in Hořava-Lifshitz cosmology

Journal Article · Mon Mar 01 04:00:00 EST 2010 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2010/03/013· OSTI ID:22273012

Wang, Anzhong ^[1]; Wands, David; Maartens, Roy ^[2]

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1. GCAP-CASPER, Physics Department, Baylor University, Waco, TX 76798-7316 (United States)
2. Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom)

We study perturbations of a scalar field cosmology in Hořava-Lifshitz gravity, adopting the most general setup without detailed balance but with the projectability condition. We derive the generalized Klein-Gordon equation, which is sixth-order in spatial derivatives. Then we investigate scalar field perturbations coupled to gravity in a flat Friedmann-Robertson-Walker background. In the sub-horizon regime, the metric and scalar field modes have independent oscillations with different frequencies and phases except in particular cases. On super-horizon scales, the perturbations become adiabatic during slow-roll inflation driven by a single field, and the comoving curvature perturbation is constant.

• OSTI ID: 22273012
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 03 Vol. 2010; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
COSMOLOGY
DISTURBANCES
GRAVITATION
INFLATIONARY UNIVERSE
KLEIN-GORDON EQUATION
METRICS
OSCILLATIONS
SCALAR FIELDS