Modified gravitational wave propagation: information from strongly lensed binaries and the BNS mass function

TL;DR

This paper discusses how gravitational wave observations, especially from strongly lensed binaries and the neutron star mass function, can test modifications of gravity at cosmological scales, with current and future detectors providing increasingly precise measurements.

Contribution

It introduces methods to test modified gravitational wave propagation using current and upcoming gravitational wave detectors, highlighting the potential for high-precision measurements of the  parameter.

Findings

Current detectors can estimate  with interesting accuracy.

Next-generation detectors like the Einstein Telescope can achieve sub-percent precision.

Modified gravity effects can be probed through gravitational wave observations.

Abstract

Modified gravitational wave propagation is a smoking gun of modifications of gravity at cosmological scales, and can be the most promising observable for testing such theories. The observation of gravitational waves (GW) in recent years has allowed us to start probing this effect, and here we briefly review two promising ways of testing it. We will show that, already with the current network of detectors, it is possible to reach an interesting accuracy in the estimation of the $\Xi_0$ parameter (that characterizes modified gravitational wave propagation, with $\Xi_{0, {\rm GR}} = 1$) and with next generation facilities, such as the Einstein Telescope, we can get a sub-percent measurement.