Testing the consistency of cosmological models with multimessenger astronomy

TL;DR

This paper derives general consistency conditions between gravitational wave and electromagnetic luminosity distances within the Friedmann cosmological model, testing model assumptions like flatness and the cosmological constant.

Contribution

It introduces new multimessenger consistency relations that are independent of dark energy equations of state and flatness assumptions.

Findings

Derived a relation for the curvature parameter from GW and EMW distances.

Established a flatness-independent consistency relation for the Friedmann model.

Formulated a general consistency relation for the cosmological constant.

Abstract

We show that within the framework of the Friedmann cosmological model it is possible to derive general multimessenger consistency conditions, between the gravitational wave (GW) and the electromagnetic wave (EMW) luminosity distances. We first study the effects of the flatness assumption often used in the estimation of cosmological parameters from GWs observations, deriving a general relation for the curvature parameter, uniquely in terms of the flatness biased GW and the EMW luminosity distances, and a multimessenger consistency relation for the Friedmann model, valid independently of the dark energy equation of state. We then derive a general multimessenger consistency relation for the cosmological constant, which is independent of any flatness assumption made in the analysis of observational data.