Searching for new physics during gravitational waves propagation

TL;DR

This paper investigates how gravitational waves might disperse during propagation, testing various theories beyond general relativity by analyzing multimessenger and GW-only events to set constraints on new physics.

Contribution

It provides new constraints on alternative gravity theories, including extra-dimensional, scalar-tensor, and Lorentz-violating models, using recent gravitational wave observations.

Findings

Constraints on theories predicting gravitational wave dispersion.

Best limits on graviton mass from GW data.

No evidence found for Lorentz violation in gravitational wave propagation.

Abstract

The direct detection of gravitational waves by ground-based interferometers opened an unprecedented channel to probe alternative theories of gravitation. Several theories predict a dispersion of the gravitational waves during their propagation, distorting the signals observed by LIGO and Virgo compared to their predictions from general relativity. Such dispersion could induce a modification of the luminosity distance inferred with gravitational radiation with regards to electromagnetic radiation. By analysing two multimessenger events, we set constraints on a large class of proposed theories, including extra-dimensional and scalar-tensor theories. The multimessenger events are the binary neutron star merger GW170817 associated to GRB170817A, and the binary black hole merger GW190521 with postulated candidate electromagnetic counterpart ZTF19abanrhr. Without relying on multimessenger emission, a class of proposed theories predict a frequency-dependent dispersion of the gravitational waves breaking Lorentz invariance. By analysing 31 GW events from binary-black holes coalescence, we constrain several coefficients parameterising Lorentz violation, including the best constraint on the graviton mass.