General relativity predicts Gravitational waves (GWs) to propagate through the Friedmann–Lemaître–Robertson–Walker (FLRW) metric as a spherical wave at the speed of light and with a friction term given by the expansion of the universe. However, several modified gravity theories (such as massive gravity or effective field theories in the dark energy sector), modify the friction term and the...
The minimal theory of massive gravity (MTMG) is a theory of massive gravity that displays only the two canonical tensor degrees of freedom.Thus it provides a natural explanation for the late-time acceleration (via the graviton's mass) while passing with flying colors the bounds of GW170817 + GRB170817A, as the speed of GW is exactly 1. As this theory was constructed for cosmological purposes,...
