ar X iv : a st ro - p h / 97 04 25 4 v 1 2 5 A pr 1 99 7 Upper limit to Ω B in scalar - tensor gravity theories

ar X iv : a st ro - p h / 99 02 29 8 v 2 1 3 A pr 1 99 9 New limits on Ω Λ and Ω M from old galaxies at high redshift

ar X iv : a st ro - p h / 99 04 24 4 v 1 1 9 A pr 1 99 9 Is SGR 1900 + 14 a Magnetar ?

We present RXTE observations of the soft gamma–ray repeater SGR

ar X iv : a st ro - p h / 97 06 04 5 v 1 4 J un 1 99 7 The Implications of Direct Red - Shift Measurement of γ - ray Bursts

Received ; accepted – 2 – ABSTRACT The recent discoveries of X-ray and optical counterparts for GRBs, and a possible discovery of a host galaxy, implies that a direct measurement of the red-shift of some GRBs host galaxies is eminent. We discuss the implications of such measurements. They could enable us to determine the GRBs luminosity distribution, the variation of the rate of GRBs with cosmi...

ar X iv : a st ro - p h / 97 11 24 4 v 1 2 0 N ov 1 99 7 POPULATION SYNTHESIS OF HIGH ENERGY TRANSIENTS RELATIVISTIC BINARY MERGING RATES

ar X iv : a st ro - p h / 96 05 07 0 v 2 1 7 Ju n 19 96 A time – dependent Cosmological ” Constant ”

We extend the Wald cosmic no–hair theorem to a general class of scalar–tensor nonminimally coupled theories of gravity where ordinary matter is also present in the form of a perfect fluid. We give a set of conditions for obtaining a de Sitter expansion independently of any initial conditions, generalizing the treatment of such a problem as given by Wald. Finally we apply the results to some spe...