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 study the effect of a void network on the CMB anisotropy in the Einstein-de Sitter background using Thompson & Vishniac’s model. We consider comprehensively the Sacks-Wolfe effect, the Rees-Sciama effect and the gravitational lensing effect. Our analysis includes the model of primordial voids existing at recombination, which is realized in some inflationary models associated with a first-ord...