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arXiv · 1810.07971

Lorentz symmetry is relevant

Benjamin Knorr
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Abstract

We set up a covariant renormalisation group equation on a foliated spacetime which preserves background diffeomorphism symmetry. As a first application of the new formalism, we study the effect of quantum fluctuations in Lorentz symmetry breaking theories of quantum gravity. It is found that once a small breaking is introduced e.g. at the Planck scale, quantum fluctuations enhance this breaking at low energies. A numerical analysis shows that the magnification is of order unity for trajectories compatible with a small cosmological constant. The immediate consequence is that the stringent observational constraints on Lorentz symmetry breaking are essentially scale-independent and must be met even at the Planck scale.

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Benjamin Knorr. 2018-10-18. Lorentz symmetry is relevant. https://doi.org/10.1016/j.physletb.2019.01.070

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