2009/09/30 by Anzhong Wang, David Wands, Roy Maartens · 8 citations
Physics and Astronomy · #Advanced Differential Geometry Research #Black Holes and Theoretical Physics #Cosmological perturbation theory #Cosmology #Cosmology and Gravitation Theories #Inflation (cosmology) #Perturbation (astronomy) #Scalar (mathematics) #Scalar field #Scalar theories of gravitation #astro-ph.CO #f(R) gravity #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2010/03/013
published as JCAP 1003:013,2010 · Revtex4, no figures. Version published in JCAP 03, 013 (2010).
openalex publication_date 2010/03/09 · arxiv created 2010/04/23 · arxiv updated 2010/04/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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.