ar X iv : g r - qc / 9 21 00 14 v 1 2 4 O ct 1 99 2 Brown - HET - 876 September 1992 A NONSINGULAR UNIVERSE ⋆

ar X iv : g r - qc / 9 40 50 04 v 2 3 N ov 1 99 4 BROWN - HET - 942 April 1994 Singularity - Free Two Dimensional Cosmologies

We present a class of theories of two dimensional gravity which admits homogeneous and isotropic solutions that are nonsingular and asymptotically approach a FRW matter dominated universe at late times. These models are generalizations of two dimensional dilaton gravity and both vacuum solutions and those including conformally coupled matter are investigated. In each case our construction leads...

ar X iv : g r - qc / 9 20 90 02 v 2 3 1 O ct 1 99 2 Black string traveling waves

A family of solutions to low energy string theory is found. These solutions represent waves traveling along “extremal black strings.” 2

ar X iv : g r - qc / 9 21 20 13 v 1 2 1 D ec 1 99 2 Inhomogeneous and anisotropic cosmologies

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 / 9 71 00 14 v 1 2 O ct 1 99 7 A CRITICAL LOOK AT MASSIVE SCALAR FIELD COLLAPSE

We present the findings of an investigation of critical behavior in the collapse of spherically symmetric distributions of massive scalar field. Two distinct types of phase transition are observed at the verge of black hole formation and a criterion for determining when each type of transition will occur is given.