Comment on `Strong coupling in extended Horava-Lifshitz gravity'

TL;DR

This paper refutes previous claims of strong coupling issues in an extended Horava-Lifshitz gravity model, demonstrating it remains weakly coupled under observational constraints and is potentially viable as a quantum gravity theory.

Contribution

It provides a critical correction to prior assertions, showing the model does not have strong coupling problems and establishing bounds for its ultraviolet scale based on observational data.

Findings

The model is weakly coupled within certain parameter bounds.

Observational constraints define the ultraviolet scale limits.

The model remains phenomenologically viable and renormalizable.

Abstract

We show that, contrary to the claim made in arXiv:0911.1299, the extended Horava gravity model proposed in arXiv:0909.3525 does not suffer from a strong coupling problem. By studying the observational constraints on the model we determine the bounds on the scale of the ultraviolet modification for which the proposal yields a phenomenologically viable, renormalizable and weakly coupled model of quantum gravity.