2009/11/28 by Xian Gao, Yi Wang, Wei Xue +1 · 56 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmological perturbation theory #Cosmology #Cosmology and Gravitation Theories #Curvature #Gravitation #Induced gravity #Metric (unit) #Noncommutative and Quantum Gravity Theories #Quantum fluctuation #Quantum gravity #Realization (probability) #Scalar (mathematics) #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2010/02/020
published in Journal of Cosmology and Astroparticle Physics 2010(02), 020 (Institute of Physics) · 19 pages
arxiv created 2009/11/28 · openalex publication_date 2010/02/15 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Hořava-Lifshitz gravity is a potentially UV complete theory with important implications for the very early universe. In particular, in the presence of spatial curvature it is possible to obtain a non-singular bouncing cosmology. The bounce is realized as a consequence of higher order spatial curvature terms in the gravitational action. Here, we extend the study of linear cosmological perturbations in Hořava-Lifshitz gravity coupled to matter in the case when spatial curvature is present. As in the case without spatial curvature, we find that there is no extra dynamical degree of freedom for scalar metric perturbations. We study the evolution of fluctuations through the bounce and show that the solutions remain non-singular throughout. If we start with quantum vacuum fluctuations on sub-Hubble scales in the contracting phase, and if the contracting phase is dominated by pressure-less matter, then for λ = 1 and in the infrared limit the perturbations at late times are scale invariant. Thus, Hořava-Lifshitz gravity can provide a realization of the ``matter bounce'' scenario of structure formation.