Scale-invariant cosmological perturbations from Hořava-Lifshitz gravity without inflation

By S. Mukohyama. 2009

235 citations recorded by the source corpus.

Based on the renormalizable theory of gravitation recently proposed by Ho?ava, we present a simple scenario to generate almost scale-invariant, super-horizon curvature perturbations. The anisotropic scaling with dynamical critical exponent z = 3 implies that the amplitude of quantum fluctuations of a free scalar field generated in the early epoch of the expanding universe is insensitive to the Hubble expansion rate and, thus, scale-invariant. Those fluctuations are later converted to curvature perturbations by the curvaton mechanism or/and the modulated decay of heavy particles/oscillating fields. This scenario works, for example, for power law expansion at p with 1/3$> p>1/3 and, thus, does not require inflation. Also, this scenario does not rely on any additional assumptions such as the detailed balance condition.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/533448e79fee13a94805b6df9a9cdf924cd13dbe

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Citations in the corpus

Dark matter as integration constant in Horava-Lifshitz gravity (2009, unknown): “For example, the z = 3 Lifshitz scaling not only is the origin of the power-counting renormalizability but also leads to a number of interesting cosmological consequences, such as generation of scale-invariant cosmological perturbations from a non-inflationary epoch of the early universe [7] and a p”
Modified Gravity and Cosmology (2011, background): “Cosmological perturbations in HL gravity have also been considered (see, for example, [925, 284, 521, 1257, 712, 1258, 713, 1256, 632, 652]).”
Phenomenological aspects of Hořava–Lifshitz cosmology (2009, methodology): “For example, cosmology based on Hořava-Lifshitz gravity was investigated in [2, 3, 4, 5, 6, 7, 8, 9, 10].”
Non-singular cosmology in a model of non-relativistic gravity (2009, background): “[57, 58] and references therein for the perturbations of a pure expanding universe in Hořava-Lifshitz cosmology.”
Quantum gravity without Lorentz invariance (2009, background): “Would there be non-zero signals in Eötvös-type experiments? Apart from these questions, the community has already begun to look at such things as the possible generation of chiral gravitational waves [5], possible impacts on cosmological solutions and perturbations [6, 7, 9, 10, 16, 17, 21, 28, 36],”
On the z=4 Horava-Lifshitz Gravity (2009, unknown): “1Email: cairg@itp.ac.cn 2Email: liuyan@itp.ac.cn 3Email: sunyw@itp.ac.cn”
The black hole and cosmological solutions in IR modified Hořava gravity (2009, background): “Since then various aspects and solutions have been studied [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29].”
Field theory at a Lifshitz point (2009, background): “An interesting result is that the perturbation of the scalar field with z = 3 is scale invariant in the universe where the scale factor goes like a(t) ∼ t with p > 1/3 [8].”