Constraining Horava-Lifshitz gravity from neutrino speed experiments

Understand

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.