Constraining Horava-Lifshitz gravity from neutrino speed experiments

TL;DR

This paper uses neutrino speed measurements from OPERA and ICARUS to place constraints on Horava-Lifshitz gravity, focusing on fermion propagation and ruling out certain parameter regions of the theory.

Contribution

It provides the first constraints on Horava-Lifshitz gravity parameters based on neutrino speed experiments, especially analyzing the Dirac equation in spherical solutions.

Findings

Excluded parameter regions are very narrow.

Detailed balance case is in the excluded region.

Neutrinos propagate effectively in a metric that could allow superluminal speeds.

Abstract

We constrain Horava-Lifshitz gravity using the results of OPERA and ICARUS neutrino speed experiments, which show that neutrinos are luminal particles, examining the fermion propagation in the earth's gravitational field. In particular, investigating the Dirac equation in the spherical solutions of the theory, we find that the neutrinos feel an effective metric with respect to which they might propagate superluminally. Therefore, demanding not to have superluminal or subluminal motion we constrain the parameters of the theory. Although the excluded parameter regions are very narrow, we find that the detailed balance case lies in the excluded region.