Using the principle of energy conservation has been considered for gravity field determination from satellite observations since the early satellite era. CHAMP is the first satellite to which the energy balance approach can be usefully applied, now that near-continuous orbit tracking by GPS is available, aided by accelerometry. The feasibility of this approach has recently been demonstrated. Th...

We calculate the shear viscosity of field theories with gravity duals of Gauss-Bonnet gravity with a non-trivial dilaton using AdS/CFT. We find that the dilaton filed has a non-trivial contribution to the ratio of shear viscosity over entropy density and after imposing causal constraint for the boundary field theory, the new lower bound 4/25π, obtained from pure Gauss-Bonnet gravity, may have a...

The quantum field theory of gravitation is constructed in terms of Lagrangian density of Dirac fields which couple to the electromagnetic field Aμ as well as the gravitational field G. The gravity appears in the mass term as m(1+gG)ψ̄ψ with the coupling constant of g. In addition to the gravitational force between fermions, the electromagnetic field Aμ interacts with the gravity as the fourth or...

Gravity theory is the basis of modern cosmological models. Thirring-Feynman’s tensor field approach to gravitation is an alternative to General Relativity (GR). Though Field Gravity (FG) approach is still developing subject, it opens new understanding of gravitational interaction, stimulates novel experiments on the nature of gravity and gives possibility to construct new cosmological models in...

The first 111 days of preliminary data from GRACE were used to produce a map of the Earth’s gravity anomalies. A gravity anomaly map shows us how much the actual Earth’s gravity field departs from “normal” as defined by a simplified mathematical gravity model that assumes the Earth is perfectly smooth and featureless. In this grayscale representation, brighter areas represent positive gravity a...