Constraining the Kehagias-Sfetsos solution in the Horava-Lifshitz gravity with extrasolar planets

TL;DR

This paper uses the orbital data of the exoplanet HD209458b to set a lower bound on a parameter in the Kehagias-Sfetsos solution of Horava-Lifshitz gravity, testing deviations from general relativity.

Contribution

It derives a correction to Kepler's third law from HL gravity and applies it to observational data to constrain the theory's parameters.

Findings

Lower bound on KS parameter    1.4^{-18}

Method to compare HL gravity predictions with exoplanet orbital data

Suggestion for re-analyzing exoplanet data with HL gravity models

Abstract

We consider a spherically symmetric and asymptotically flat vacuum solution of the Horava-Lifshitz (HL) gravity that is the analog of the general relativistic Schwarzschild black hole. In the weak-field and slow-motion approximation, we work out the correction to the third Kepler law of a test particle induced by such a solution and compare it to the phenomenologically determined orbital period of the transiting extrasolar planet HD209458b Osiris to preliminarily obtain an order-of-magnitude lower bound on the KS dimensionless parameter \omega_0 >= 1.4\times 10^-18. As suggestions for further analyses, the entire data set of HD209458b should be re-processed by explicitly modeling KS gravity as well, and one or more dedicated solve-for parameter(s) should be estimated.