The four observables associated with gravitational lensing of distant quasars by intervening galaxies: image splittings, relative amplifications, time delays, and optical depths, provide separate measures of the strength of the gravitational constant G at cosmological distances. These allow one, in principle, to factor out unknown lensing parameters to directly to probe the variation of G over ...

We discuss in detail the semiclassical approximation for the CGHS model of two-dimensional dilatonic black holes. This is achieved by a formal expansion of the full Wheeler-DeWitt equation and the momentum constraint in powers of the gravitational constant. In highest order, the classical CGHS solution is recovered. The next order yields a functional Schrödinger equation for quantum fields prop...

An improved formula for the timing of binary pulsars that accounts for the relativistic deflection of light in the gravitational field of the pulsar’s companion is presented, and the measurability of this effect together with its variance estimates are discussed. The deflection of the pulsar’s beam trajectory in the gravitational field of its companion leads to variation in the pulsar’s rotatio...

Gravitational search algorithm (GSA) is one of the newest swarm based optimization algorithms, which has been inspired by the Newtonian laws of gravity and motion. GSA has empirically shown to be an efficient and robust stochastic search algorithm. Since introducing GSA a convergence analysis of this algorithm has not yet been developed. This paper introduces the first attempt to a formal conve...

Gravitational search algorithm (GSA) is one of the newest swarm based optimization algorithms, which has been inspired by the Newtonian laws of gravity and motion. GSA has empirically shown to be an efficient and robust stochastic search algorithm. Since introducing GSA a convergence analysis of this algorithm has not yet been developed. This paper introduces the first attempt to a formal conve...

We predict the amplitude of the gravitational redshift of galaxies in galaxy clusters using an N-body simulation of ΛCDM universe. We examine if it might be possible to detect the gravitational effect on the total redshift observed for galaxies. For clusters of mass M ∼ 10hM⊙, the difference in gravitational redshift between the brightest galaxy and the rest of the cluster members is ∼ 10 km s....

We present a novel method to reconstruct the mass distribution of galaxy clusters from their gravitational lens effect on background galaxies. The method is based on a least-x 2 fit of the two-dimensional gravitational cluster potential. The method combines information from shear and magnification by the cluster lens and is designed to easily incorporate possible additional information. We desc...

The detection of some tiny gravitomagnetic effects in the field of the Earth by means of artificial satellites is a very demanding task because of the various other perturbing forces of gravitational and non-gravitational origin acting upon them. Among the gravitational perturbations a relevant role is played by the Earth solid and ocean tides. In this communication I outline their effects on t...

In this paper the dynamic of a droplet on a surface with a hole is investigated under gravitational effect by using lattice Boltzmann method. Incompressible two-phase flow with high density ratio proposed by Lee is considered. Cahn’s theory is used to observe the wettability of the surface in contact with liquid and gas phases. Several parameters such as contact angle, surface tension and gravi...

Experimental discovery of the gravitomagnetic fields generated by translational and/or rotational currents of matter is one of primary goals of modern gravitational physics. The rotational (intrinsic) gravitomagnetic field of the Earth is currently measured by the Gravity Probe B. The present paper makes use of a parametrized post-Newtonian (PN) expansion of the Einstein equations to demonstrat...