ar X iv : g r - qc / 0 21 00 45 v 1 1 5 O ct 2 00 2 Cosmological Parameters are Dressed

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 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 21 00 04 v 1 2 O ct 2 00 2 TIME DEPENDENCE OF BRANS - DICKE PARAMETER ω FOR AN EXPANDING UNIVERSE

We have studied the time dependence of ω for an expanding universe in the generalised B-D theory and have obtained its explicit dependence on the nature of matter contained in the universe in different era.Lastly, we discuss how the observed accelerated expansion of the present universe can be accomodated in the formalism.

ar X iv : g r - qc / 0 31 00 75 v 1 1 5 O ct 2 00 3 BOUNDARIES ON SPACETIMES : AN OUTLINE

The causal boundary construction of Geroch, Kronheimer, and Penrose has some universal properties of importance for general studies of spacetimes, particularly when equipped with a topology derived from the causal structure. Properties of the causal boundary are detailed for spacetimes with spacelike boundaries, for multi-warped spacetimes, for static spacetimes, and for spacetimes with group a...

ar X iv : g r - qc / 0 21 00 36 v 1 1 1 O ct 2 00 2 LINKING , LEGENDRIAN LINKING AND CAUSALITY

The set N of all null geodesics of a globally hyperbolic (d + 1)-dimensional spacetime (M, g) is naturally a smooth (2d − 1)-dimensional contact manifold. The sky of an event x ∈ M is the subset X = {γ ∈ N : x ∈ γ} ⊂ N and is an embedded Legendrian submanifold of N diffeomorphic to S d−1. It was conjectured by Low that for d = 2 events x, y ∈ M are causally related iff X, Y ⊂ N are linked (in a...