A relativistic sub-picosecond model of gravitational time delay in radio astronomical observations is worked out and a new experimental test of general relativity is discussed in which the effect of retardation of gravity associated with its finite speed can be observed. As a consequence, the speed of gravity can be measured by differential VLBI observations. Retardation in propagation of gravi...

The generation, as well as the detection, of gravitational radiation by means of charged superfluids is considered. One example of such a “charged superfluid” consists of a pair of Planck-mass-scale, ultracold “Millikan oil drops,” each with a single electron on its surface, in which the oil of the drop is replaced by superfluid helium. When levitated in a magnetic trap, and subjected to microw...

William Fairbank is tremendously lucky-or is he clairvoyant? He initiated the Stanford gyroscope experiment in 1961 as a search for the dragging of inertial frames by the earth's rotation-an effect so small as to be interesting in principle, but not in practice. However, today, twenty years later, just when technology development for the gyroscope experiment has reached completion, the theoreti...

In Brans–Dicke theory the Universe becomes divided after inflation into many exponentially large domains with different values of the effective gravitational constant. Such a process can be described by diffusion equations for the probability of finding a certain value of the inflaton and dilaton fields in a physical volume of the Universe. For a typical chaotic inflation potential, the solutio...

We investigate the possibility that dark energy does not couple to gravitation in the same way as ordinary matter, yielding a violation of the weak and strong equivalence principles on cosmological scales. We build a transient mechanism in which gravitation is pushed away from general relativity by a Born-Infeld gauge interaction acting as an abnormally weighting (dark) energy. This mechanism a...

Torsion gravitational effects in the quantum interference of charged particles are investigated. The influence of axial torsion in the Schiff-Banhill effect (SB) inside a metallic shell is given. The effect of torsion on the surface of the earth on (SB) experiment is estimated. Torsion gravity effects on the Sagnac phase-shift of neutron interferometry are also computed.

Large-scale gravitational-wave detectors currently under construction such as the LIGO detectors use multiplemirror resonant optical systems containing several surfaces at which the relative phase of interfering light beams must be controlled. We describe a tabletop experiment that demonstrates a scheme for extracting signals in such an interferometer corresponding to deviations from perfect in...