# Constraints on higher curvature gravity from time delay between GW170817 and GRB 170817A

## TL;DR

This paper uses the observed time delay between GW170817 and GRB 170817A to place constraints on higher curvature modifications to general relativity, providing a general method applicable to various theories.

## Contribution

It introduces a general approach to constrain higher curvature gravity theories using gravitational-electromagnetic time delay observations.

## Key findings

- Constraints on higher curvature coupling constants derived from GW and GRB data
- Method applicable to a wide class of higher curvature theories
- Demonstrates the potential of multi-messenger observations to test gravity theories

## Abstract

General relativity may be an effective theory with higher curvature correction terms in the action. Inclusion of these terms leads to exciting new possibilities, e.g., gravitational and electromagnetic perturbations following different geodesics; leading to a time delay. Such a time delay was observed between the gravitational wave event GW170817 and its electromagnetic counterpart GRB 170817A. We describe how this effect can be used to constrain the coupling of the higher curvature term. Our method is sufficiently general and applicable to any higher curvature theory.