Cuscuton and low-energy limit of Horava-Lifshitz gravity

Journal Article · Thu Oct 15 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.80.081502· OSTI ID:21325299

Afshordi, Niayesh ^[1]

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1. Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON, N2L 2Y5 (Canada)

Horava-Lifshitz theory has been recently put forth as a proposal for a renormalizable theory of quantum gravity 1. It explicitly breaks Lorentz invariance, introducing an apparent extra scalar degree of freedom. I show that the low energy limit of (non-projectible) Horava-Lifshitz gravity is uniquely given by the quadratic cuscuton model: a covariant scalar field theory with an infinite speed of sound and a quadratic potential, minimally coupled to Einstein gravity. This implies that the extra scalar is nondynamical to all orders in perturbation theory. Cosmological constraints on the quadratic cuscuton model constrain the low energy Lorentz breaking parameter of Horava-Lifshitz theory to |{lambda}-1|<0.014. We also point out that the spatial hypersurfaces are constant mean curvature or uniform expansion surfaces and introduce geometrical symmetries that can protect the nondynamical nature of these theories.

• OSTI ID: 21325299
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 8 Vol. 80; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DEGREES OF FREEDOM
EXPANSION
GENERAL RELATIVITY THEORY
GRAVITATION
LORENTZ INVARIANCE
PERTURBATION THEORY
PROGRAMMING LANGUAGES
QUANTUM FIELD THEORY
QUANTUM GRAVITY
SCALAR FIELDS
SOUND WAVES
SURFACES
SYMMETRY
VELOCITY