It is shown that if a generalized definition of gauge invariance is used, gauge invariant effective stress-energy tensors for gravitational waves and other gravitational perturbations can be defined in a much larger variety of circumstances than has previously been possible. In particular it is no longer necessary to average the stress-energy tensor over a region of spacetime which is larger in...

A gravity theory is developed with the metric ĝμν = gμν+B∂μφ∂νφ. In the present universe the additional contribution from the scalar field in the metric ĝμν can generate an acceleration in the expansion of the universe, without negative pressure and with a zero cosmological constant. In this theory, gravitational waves will propagate at a different speed from non-gravitational waves. It is sugg...

We present numerical three-body experiments that include the effects of gravitational radiation reaction by using equations of motion that include the 2.5-order post-Newtonian force terms, which are the leading-order terms of energy loss from gravitational waves. We simulate binary-single interactions and show that close-approach cross sections for three 1 M objects are unchanged from the purel...

The first direct observation of gravitational waves’ action upon matter has recently been reported by the BICEP2 experiment. Advanced ground-based gravitational-wave detectors are being installed. They will soon be commissioned, and then begin searches for high-frequency gravitational waves at a sensitivity level that is widely expected to reach events involving compact objects like stellar mas...

A gravity theory is developed with the metric ĝμν = gμν+B∂μφ∂νφ. In the present universe the additional contribution from the scalar field in the metric ĝμν can generate an acceleration in the expansion of the universe, without negative pressure and with a zero cosmological constant. In this theory, gravitational waves will propagate at a different speed from non-gravitational waves. It is sugg...

Since gravitational waves are solutions of Einstein’s field equations with a zero stress-energy tensor, the reality of these waves was questioned. To demonstrate it, the momentum imparted to test particles by such waves was evaluated. A closed form expression for this quantity was provided by Qadir and Sharif, using an extension of the pseudo-Newtonian formalism. That formalism carried with it ...