Tolman-Ehrenfest’s criterion of thermal equilibrium extended to conformally static spacetimes

Recollapse of the Closed Tolman Spacetimes

The closed-universe recollapse conjecture is studied for the spherically symmetric spacetimes. It is proven that there exists an upper bound to the lengths of timelike curves in any Tolman spacetime that possesses S3 Cauchy surfaces and whose energy density is positive. Furthermore, an explicit bound is constructed from the initial data for such a spacetime. 04.20.Cv, 04.20.Jb, 98.80.Hw Typeset...

On Cauchy Surfaces in Conformally Stationary Spacetimes

A criterion for a spacelike hypersurface in a conformally stationary spacetime to be a Cauchy hypersurface is given. The criterion is based on the forward and the backward completeness of a non-reversible Finsler metric associated to the hypersurface.

Note on (conformally) semi-symmetric spacetimes

We prove that conformally semi-symmetric spacetimes are actually semisymmetric. We also present a complete refined classification of the semi-symmetric spacetimes. PACS numbers: 04.20.Cv, 02.40.Ky, 04.20.Jb

Spherically Symmetric Static Spacetimes

In this paper we discuss matter inheritance collineations by giving a complete classification of spherically symmetric static spacetimes by their matter inheritance symmetries. It is shown that when the energy-momentum tensor is degenerate, most of the cases yield infinite dimensional matter inheriting symmetries. It is worth mentioning here that two cases provide finite dimensional matter inhe...

Multipole Moments of Static Spacetimes