Fluctuations in a Hořava-Lifshitz bouncing cosmology
- Key Laboratory of Frontiers in Theoretical Physics, Chinese Academy of Sciences, Zhong Guan Cun East Street 55, Beijing 100190 (China)
- Physics Department, McGill University, 3600 rue University, Montreal, QC, H3A 2T8 (Canada)
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.
- OSTI ID:
- 22272986
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 02; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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