A healthy extension of Horava gravity

TL;DR

This paper introduces a modified version of Horava gravity that is free from previous issues, maintains renormalizability, and closely approximates general relativity at low energies by adjusting parameters.

Contribution

It presents a natural extension of Horava gravity with a well-behaved scalar mode and improved theoretical consistency, addressing past pathologies.

Findings

Scalar graviton mode has a regular quadratic action.

Model remains power-counting renormalizable.

Deviations from general relativity can be minimized.

Abstract

We propose a natural extension of Horava's model for quantum gravity, which is free from the notorious pathologies of the original proposal. The new model endows the scalar graviton mode with a regular quadratic action and remains power-counting renormalizable. At low energies, it reduces to a Lorentz-violating scalar-tensor gravity theory. The deviations with respect to general relativity can be made weak by an appropriate choice of parameters.