Modified Gravity (MOG), the speed of gravitational radiation and the event GW170817/GRB170817A

TL;DR

This paper discusses Modified Gravity (MOG), a relativistic alternative to general relativity, demonstrating its consistency with the GW170817/GRB170817A event and addressing claims about its gravitational wave speed.

Contribution

It shows that MOG satisfies the weak equivalence principle and aligns with observations of neutron star mergers, countering recent claims about its gravitational wave propagation.

Findings

MOG is consistent with GW170817/GRB170817A observations.

MOG satisfies the weak equivalence principle.

MOG's gravitational waves travel at the speed of light.

Abstract

Modified gravity (MOG) is a covariant, relativistic, alternative gravitational theory whose field equations are derived from an action that supplements the spacetime metric tensor with vector and scalar fields. Both gravitational (spin 2) and electromagnetic waves travel on null geodesics of the theory's one metric. Despite a recent claim to the contrary, MOG satisfies the weak equivalence principle and is consistent with observations of the neutron star merger and gamma ray burster event GW170817/GRB170817A.