Comparing the luminosity distance for gravitational waves and electromagnetic signals in a simple model of quadratic gravity

TL;DR

This paper investigates how quadratic gravity modifications affect the luminosity distance measurements for gravitational waves compared to electromagnetic signals, highlighting potential deviations from standard cosmology.

Contribution

It introduces a generalized cosmological model with quadratic curvature corrections and analyzes their impact on gravitational wave luminosity distances.

Findings

Quadratic gravity alters the friction coefficient for tensor perturbations.

Differences between gravitational and electromagnetic luminosity distances are quantified.

Numerical estimates show deviations at redshifts relevant for Supernovae and standard sirens.

Abstract

We compute the modified friction coefficient controlling the propagation of tensor metric perturbations in the context of a generalized cosmological scenario based on a theory of gravity with quadratic curvature corrections. In such a context we discuss the differences between gravitational and electromagnetic luminosity distance, as well as the differences with the standard results based on the Einstein equations. We present numerical estimates of the modified luminosity distance on the cosmic redshift scale typical of Supernovae and standard sirens.