The first successful detection of gravitational waves (GWs) opened up a new window to study realm the most violent phenomena in universe, such as coalescences binary black holes (BH–BH), neutron stars (NS–NS), and mixed (BH–NS) systems, which are mostly inaccessible electromagnetic window. On other hand, strong lensing distant sources, galaxies quasars, by massive objects lying closer along lin...

Extreme 4-dimensional dilaton black holes embedded into 10-dimensional geometry are shown to be dual to the gravitational waves in string theory. The corresponding gravitational waves are the generalization of pp-fronted waves, called supersymmetric string waves. They are given by Brinkmann metric and the twoform field, without a dilaton. The non-diagonal part of the metric of the dual partner ...

We provide a completely quantum-mechanical derivation of the spectrum of gravitational waves produced in any inflationary cosmology. The gravitational waves result from a sequence of Bogoliubov transformations between creation and annihilation operators defined in de Sitter space and in radiation-and matter-dominated Robertson-Walker spacetimes. We discuss how the results depend on the initial ...

This review is focused on tests of Einstein's theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein's theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previousl...

We describe a method by which gravitational wave observations of eccentric binary systems could be used to test General Relativity’s prediction that gravitational waves are dispersionless. We present our results in terms of the graviton having a non-zero rest mass, or equivalently a non-infinite Compton wavelength. We make a rough estimate of the bounds that might be obtained following gravitat...

We review the tests of general relativity that will become possible with space-based gravitational-wave detectors operating in the ∼ 10-5 - 1 Hz low-frequency band. The fundamental aspects of gravitation that can be tested include the presence of additional gravitational fields other than the metric; the number and tensorial nature of gravitational-wave polarization states; the velocity of prop...

Largely motivated by the development of highly sensitive gravitational-wave detectors, our understanding of merging compact binaries and the gravitational waves they generate has improved dramatically in recent years. Breakthroughs in numerical relativity now allow us to model the coalescence of two black holes with no approximations or simplifications. There has also been outstanding progress ...