ar X iv : g r - qc / 0 50 90 96 v 2 1 3 O ct 2 00 5 Spinorial Field and Lyra Geometry

ar X iv : g r - qc / 0 51 01 27 v 1 3 1 O ct 2 00 5 Imprints of Spacetime Topology in the Hawking - Unruh Effect

ar X iv : g r - qc / 0 31 00 76 v 1 1 5 O ct 2 00 3 HOLONOMY GROUPS AND SPACETIMES

A study is made of the possible holonomy group types of a space-time for which the energy-momentum tensor corresponds to a null or non-null electromagnetic field, a perfect fluid or a massive scalar field. The case of an Einstein space is also included. The techniques developed are also applied to vacuum and conformally flat space-times and contrasted with already known results in these two cas...

ar X iv : g r - qc / 0 30 70 38 v 1 9 J ul 2 00 3 Bulk Viscous cosmological models in Lyra geometry

We have investigated an LRS Bianchi Type I models with bulk viscosity in the cosmological theory based on Lyra’s geometry. A new class of exact solutions have been obtained by considering a time-dependent displacement field for a constant value of the deceleration parameter and viscosity coefficient of bulk viscous fluid is assumed to be a power function of mass density. The physical behaviour ...

ar X iv : g r - qc / 0 11 01 18 v 1 2 7 O ct 2 00 1 Constancy of the Constants of Nature 1

The current observational and experimental limits on time variation of the constants of Nature are briefly reviewed.

ar X iv : g r - qc / 0 31 00 91 v 1 1 9 O ct 2 00 3 Semilinear wave equations on the Schwarzschild manifold I : Local Decay Estimates

The semilinear wave equation on the (outer) Schwarzschild manifold is studied. We prove local decay estimates for general (non-radial) data, deriving a-priori Morawetz type inequalities.