Simultaneous observation of gravitational and electromagnetic waves

TL;DR

This paper analyzes quantum gravity models using simultaneous gravitational and electromagnetic wave observations from a black hole merger, setting new bounds on wave velocity differences and ruling out certain non-luminal scenarios.

Contribution

It provides a model-independent analysis of quantum gravity scenarios based on dispersion relations, using observational data to constrain particle velocities and rule out specific models.

Findings

Only scenarios with at least one luminal particle are allowed.

Stringent bounds on the velocity difference between electromagnetic and gravitational waves.

Previous bounds are surpassed by the new constraints derived.

Abstract

Assuming that the short gamma-ray burst detected by the Fermi Gamma-Ray Space Telescope about 0.4 seconds after the gravitational waves observed by the LIGO and VIRGO Collaborations originated from the same black hole merger event, we perform a model-independent analysis of different quantum gravity scenarios based on (modified) dispersion relations (typical of quantum gravity models) for the graviton and the photon. We find that only scenarios where at least one of the two particles is luminal (the other being sub- or super-luminal) are allowed, while scenarios where none of the two particles is luminal are ruled out. Moreover, the physical request of having acceptable values for the quantum gravity scale imposes stringent bounds on the difference between the velocities of electromagnetic and gravitational waves, much more stringent than any previously known bound.