the earth’s gravity field dedicated missions, champ, grace and goce have opened up a new era for the study of the earth’s gravity field. the missions measure different functionals on the earth’s gravitational potential which are represented in terms of the stokes coefficients or the so-called geopotential models. the mapping process of the observations into the coefficients is called recovery o...

Accelerating masses are predicted to emit radiation as gravitational waves. It has been suggested that these waves may interact differently with quantum mechanical systems than with classical matter. The possibility that a quantum system may act as a novel transducer between electromagnetism and gravitational waves is investigated. A proposed mechanism for interconversion between the two fields...

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...

I propose the novel method of “gravitational-mass imaging” to detect and quantify luminous and dark-matter substructure in gravitational-lens galaxies. The method utilizes highly-magnified Einstein rings and arcs as sensitive probes of small perturbations in the lens potential (due to the presence of mass substructure), reconstructing the gravitational lens potential non-parametrically. Simulat...

We study spherically-symmetric structures in Conformal Gravity and in a scalar-tensor extension and gain some more insight about these gravitational theories. In both cases we analyze solutions in two systems: perfect fluid solutions and boson stars of a self-interacting complex scalar field. In the purely tensorial (original) theory we find in a certain domain of parameter space finite mass so...

We report on one year of photometric monitoring of the ultraluminous BAL quasar APM 08279+5255. The temporal sampling reveals that this gravitationally lensed system has brightened by ∼0.2 mag in 100 days. Two potential causes present themselves; either the variability is intrinsic to the quasar, or it is the result of microlensing by stars in a foreground system. The data is consistent with bo...

The interaction of mass will determine the curvature of space-time, may determine that events proceed at different rates of time at each point in space, so each has a corresponding gravitational potential time. So we can find different values of gravity (g), corresponding to different times (t), thus making a "map of time in space." The space-time is curved by present mass, causing a force of a...