ar X iv : 0 80 5 . 35 71 v 1 [ gr - q c ] 2 3 M ay 2 00 8 Contribution of Blackhole Entropy Towards Acceleration Of The Universe ∗

ar X iv : 0 71 2 . 38 38 v 3 [ gr - q c ] 3 1 M ay 2 00 8 General Transformation Formulas for Fermi - Walker Coordinates

ar X iv : 0 71 0 . 34 15 v 1 [ gr - q c ] 1 8 O ct 2 00 7 Modified gravity and the origin of inertia

Modified gravity theory is known to violate Birkhoff’s theorem. We explore a key consequence of this violation, the effect of distant matter in an Einstein-de Sitter universe on the motion of test particles. We find that when a particle is accelerated, a force is experienced that is proportional to the particle’s mass and acceleration and acts in the direction opposite to that of the accelerati...

ar X iv : 0 80 7 . 41 07 v 1 [ gr - q c ] 2 5 Ju l 2 00 8 Description of the free motion with momentums in Gödel ’ s universe

We study the geodesic motion in Gödel's universe, using conserved quantities. We give a necessary and sufficient condition for curves to be geodesic curves in terms of conserved quantities, which can be computed from the initial values of the curve. We check our result with numerical simulations too.

ar X iv : 0 80 5 . 45 05 v 1 [ gr - q c ] 2 9 M ay 2 00 8 Kerr initial data

Exploiting a 3+1 analysis of the so-called Mars-Simon tensor, conditions on a vacuum initial data set ensuring that its development is isometric to a subset of the Kerr spacetime are found. These conditions are expressed in terms of the vanishing of a positive scalar function defined on the initial data hypersurface. Applications of this result are discussed. PACS numbers: 04.20.Ex, 04.20-q, 04...

ar X iv : 0 80 5 . 36 42 v 1 [ gr - q c ] 2 3 M ay 2 00 8 From Dark Energy & Dark Matter to Dark Metric

General Relativity isn’t the definitive theory of Gravitation. The attempts to recover it, with respect to the latest observative data, leads to very strange physical entites as the Dark Energy & Dark Matter. On the other hand, the attempts to produce generalized theories gives rise to mathematical difficulties that need workarounds that generate problem from the interpretative viewpoint. We pr...