We study the gravitational radiation from gravitational collapses of rapidly rotating neutron stars induced by a phase-transition from normal nuclear matter to a mixed phase of quark and nuclear matter in the core of the stars. The study is based on self-consistent three dimensional hydrodynamic simulations with Newtonian gravity and a high resolution shock capturing scheme, and the quadrupole ...

Gravitational waves have been known to exist since the early days of general relativity. Einstein himself showed that in the weak field limit we get solutions that obey the wave equation. Despite its importance, at the present time there is only indirect evidence of the reality of gravitational waves ~such as the analyzed binary pulsar which shows a decrease in the orbital period due to the emi...

Beginning in the early 1950s, experts in the theory of general relativity debated vigorously whether the theory predicted the emission of gravitational radiation from binary star systems. For a time, doubts also arose on whether gravitational waves could carry any energy. Since radiation phenomena have played a key role in the development of 20th century field theories, it is the main purpose o...

[8] The LIGO Collaboration, “Search for gravitational-wave bursts in LIGO data from the fourth science run”, arXiv:0704.0943 (submitted to Class Quant Grav) [7] F. Beauville et al., “Detailed comparison of LIGO and Virgo Inspiral Pipelines in Preparation for a Joint Search”, arXiv:gr-qc/0701027 (submitted to Class Quant Grav) [6] F. Beauville et al., “A comparison of methods for gravitational w...

We consider space-times with two isometries which represent gravitational waves with distinct wavefronts which propagate into exact Friedmann–Robertson–Walker (FRW) universes. The geometry of possible wavefronts is analysed in detail in all three types of FRW models. In the spatially flat and open universes, the wavefronts can be planar or cylindrical; in the closed case they are toroidal. Exac...

In a series of papers Amati, Ciafaloni and Veneziano and 't Hooft conjectured that black holes occur in the collision of two light particles at planckian energies. In this paper we discuss a possible scenario for such a process by using the Chandrasekhar-Ferrari-Xanthopoulos duality between the Kerr black hole solution and colliding plane gravitational waves. We clarify issues arising in the de...

We review the different aspects of the interaction of mesoscopic quantum systems with gravitational fields. We first discuss briefly the foundations of general relativity and quantum mechanics. Then, we consider the non-relativistic expansions of the Klein-Gordon and Dirac equations in the post-Newtonian approximation. After a short overview of classical gravitational waves, we discuss two prop...

Superconducting gravimeters are the most sensitive instruments to measure surface gravity changes at low frequencies. Currently, about twenty five superconducting gravimeters are operating in the world and their global network has been developed. We investigate possible applications of the superconducting gravimeters to tests of gravitational physics. Previous experimental searches for spacial ...