Convincing evidence of a past interaction between two rich clusters A399 and A401 was recently found by the X-ray imaging observations. In this paper we examine the structure and dynamics of this pair of galaxy clusters. A mixture-modeling algorithm has been applied to obtain a robust partition into two clusters, which allows us to discuss the virial mass and velocity distribution for each clus...

In this paper we directly test the possibility that the Newtonian gravitational constant G may experience spatial variations over ranges ≈ 0.01− 5 AU in various extrasolar multi-planet systems by means of the third Kepler’s law. The answer is negative, within the experimental errors, for all the considered systems. A comparison with an analogous test previously performed in our Solar System is ...

Periodic oscillations are observed in Newton's gravitational constant G that are contemporaneous with length of day data obtained from the International Earth Rotation and Reference System (IERRS). Preliminary research has determined that the oscillatory period of G is ≈ 5.9 years (5.899 ± 0.062 years). In this paper, the oscillations are shown to be concomitant with the Earth's distance from t...

Applying the recently developed dynamical perturbation formalism on cosmological background to scalar-tensor theory, we provide a solid theoretical basis and a rigorous justification for phenomenological models of orbital dynamics that are currently used to interpret experimental measurements of the timedependent gravitational constant. We derive the field equations for the scalar-tensor pertur...

Assuming the equivalence of FRW-cosmological models and their Newtonian counterparts, we propose using the Gauss law in arbitrary dimension a general relation between the Newtonian gravitational constant G and the gravitational coupling constant κ.

We discuss an alternative formulation of the problem of quantum optical fields in a curved space-time using localized operators. We contrast this formulation with the standard approach and find observable differences for entangled states. We propose an experiment in which an entangled pair of optical pulses are propagated through nonuniform gravitational fields and find that the alternative for...

The appearance of peaks in the Fourier power spectra of various primordial fluctuations is a generic prediction of the inflationary scenario. We investigate whether future experiments, in particular the satellite experiment PLANCK, will be able to detect the possible appearance of these peaks in the Bmode polarization multipole power spectrum. This would yield a conclusive proof of the presence...

The confrontation between general relativity (and its theoretically most plausible deviations) and experimental or observational results is summarized. Some discussion is devoted to the various methodologies used in confronting theory and experiment. Both weak-field (solar system) and strong-field (binary pulsar) tests are discussed in detail. A special discussion is devoted to the cosmology of...