Beyond Concordance Cosmology with Magnification of Gravitational-Wave Standard Sirens

TL;DR

This paper proposes using gravitational-wave magnification effects to distinguish between the standard cosmological model and alternative theories like dynamical dark energy and modified gravity, with future detectors providing new constraints.

Contribution

It introduces a novel method leveraging weak-lensing magnification of gravitational waves to test and differentiate cosmological models beyond traditional approaches.

Findings

Future detectors like ET and DECIGO/BBO can constrain dark energy models.

Gravitational-wave magnification provides a new probe for cosmology.

Method improves discrimination between cosmological theories.

Abstract

We show how future gravitational-wave detectors would be able of discriminating between the concordance LCDM cosmological model and up-to-date competing alternatives, e.g. dynamical dark energy models (DE) or modified gravity theories (MG). Our method consists in using the weak-lensing magnification effect that affects a standard-siren signal because of its travelling trough the Universe's large-scale structure. As a demonstration, we present constraints on DE and MG from proposed gravitational-wave detectors, namely ET and DECIGO/BBO.