Take two scenarios: 1) A 2kg mass at rest 2) A 1kg mass accelerated to a speed such that its relatavistic mass is 2kg (0.866C) Which excerts more gravity? Now the obvoious answer is that they excert the same gravity as they have the same relativistic mass. The reason I ask, is that time dilation is affected in an inverse relationship to mass dilation. If gravity is affected by time dilation(i.e. gravity waves emitted at a lower rate) this would exactly counter the increased gravity due to the mass dilation resulting in no net change.