Séminaire de Physique Théorique

Horava-Lifshitz cosmology revisited
Shinji Mukohyama (Université de Kyoto, Japon)
Thursday 20 December 2018 15:30 -  Tours -  Salle 1180 (Bât E2)

Résumé :
Horava-Lifshitz gravity was recently proved to be renormalizable and thus is considered as a good candidate for quantum gravity. In this talk, I will revisit the cosmological implications of the theory. In particular, I will argue that (i) the anisotropic scaling with the dynamical critical exponent z=3, which renders the theory renormalizable, provides a solution to the cosmological horizon problem and leads to scale-invariant cosmological perturbations even without inflation and that (ii) the same scaling can solve the cosmological flatness problem if the initial condition of the Universe is set by a small instanton. I will also discuss how (iii) the issue of strong coupling of the scalar graviton can be solved via an analogue of the Vainshtein screening.

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