Constraints on Ho\v{r}ava-Lifshitz gravity from GRB 170817A

TL;DR

This paper constrains parameters of Hořava-Lifshitz gravity by analyzing gamma-ray burst GRB 170817A, leveraging the model's equal wave velocities to limit Lorentz invariance violation effects.

Contribution

It introduces a toy model coupling (3+1)-dimensional Hořava-Lifshitz gravity with an electromagnetic field via Kaluza-Klein reduction, enabling new constraints from astrophysical observations.

Findings

Stringent constraint on parameter β: |1−√β|<(10^{-19}−10^{-18})

Equal wave velocities for gravitational and electromagnetic waves in the model

Potential Lorentz invariance violation effects constrained by GRB 170817A data

Abstract

In this work we focus on a toy model: (3+1)-dimensional Ho\v{r}ava-Lifshitz gravity coupling with an anisotropic electromagnetic (EM) field which is generated through a Kaluza-Klein reduction of a (4+1)-dimensional Ho\v{r}ava-Lifshitz gravity. This model exhibits a remarkable feature that it has the same velocity for both gravitational and electromagnetic waves. This feature makes it possible to restrict the parameters of the theory from GRB 170817A. In this work we use this feature to discuss possible constraints on the parameter $\beta$ in the theory, by analyzing the possible Lorentz invariance violation effect of the GRB 170817A. This is achieved by analyzing potential time delay of gamma-ray photons in this event. It turns out that it places a stringent constraint on this parameter. In the most ideal case, it gives $|1-\sqrt{\beta}|<(10^{-19}-10^{-18})$.