The cosmological constant and Hořava-Lifshitz gravity

Journal Article · Thu Apr 01 04:00:00 EDT 2010 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2010/04/006· OSTI ID:22272843

Appignani, Corrado; Casadio, Roberto ^[1]

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1. Dipartimento di Fisica, Università di Bologna, via Irnerio 46, 40126 Bologna (Italy)

Hořava-Lifshitz theory of gravity with detailed balance is plagued by the presence of a negative bare (or geometrical) cosmological constant which makes its cosmology clash with observations. We argue that adding the effects of the large vacuum energy of quantum matter fields, this bare cosmological constant can be approximately compensated to account for the small observed (total) cosmological constant Λ{sub OBS}, thus resulting in a self-contained model of gravity and particle physics. Even though we cannot address the fine-tuning problem in this way, we are able to establish a relation between the smallness of Λ{sub OBS} and the scale l{sub UV} at which dimension 4 corrections to the Einstein gravity become significant for cosmology. This scale turns out to be l{sub UV} ≅ 5 l{sub P} for Λ{sub OBS} ≅ 0 and we therefore argue that the smallness of Λ{sub OBS} guarantees that Lorentz invariance is broken only at very small scales. We are also able to provide a first rough estimation for the values of the parameters of the theory μ and Λ{sub W}.

• OSTI ID: 22272843
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 04 Vol. 2010; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
APPROXIMATIONS
ASTROPHYSICS
CORRECTIONS
COSMOLOGICAL CONSTANT
COSMOLOGY
GRAVITATION
LORENTZ INVARIANCE