ar X iv : a st ro - p h / 01 01 36 9 v 2 2 5 Ja n 20 01 Large scale geometry and evolution of a universe with radiation pressure and cosmological constant

ar X iv : a st ro - p h / 01 01 36 9 v 3 2 3 N ov 2 00 1 Large scale geometry and evolution of a universe with radiation pressure and cosmological constant

In view of new experimental results that strongly suggest a non-zero cosmological constant, it becomes interesting to revisit the Friedman-Lemâıtre model of evolution of a universe with cosmological constant and radiation pressure. In this paper, we discuss the explicit solutions for that model, and perform numerical explorations for reasonable values of cosmological parameters. We also analyse...

ar X iv : a st ro - p h / 97 01 22 8 v 1 2 9 Ja n 19 97 Large - scale Structures revealed by Wavelet Decomposition 1

ar X iv : a st ro - p h / 01 10 21 1 v 1 9 O ct 2 00 1 Quintessence – the Dark Energy in the Universe ?

Quintessence – the energy density of a slowly evolving scalar field – may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea and indicate observational tests which may distinguish quintessence from a cosmological constant.

ar X iv : a st ro - p h / 01 01 43 8 v 1 2 4 Ja n 20 01 NUCLEAR

Observations of metal-poor Galactic halo stars indicate that the abundance pattern of the (heaviest) neutron-capture elements is consistent with the scaled solar system r-process abundances. Utilizing the radioactive (r-process) element thorium, age determinations have been made for several of these same stars, placing constraints on both Galactic and cosmological age estimates.

ar X iv : a st ro - p h / 01 02 30 5 v 1 1 7 Fe b 20 01 SPACE , TIME , AND MATTER : COSMOLOGICAL PARAMETERS 2001

Over the past three years, our confidence in the inferred values of cosmological parameters has increased dramatically, confirming that the flat matter dominated Universe that dominated cosmological model building for the past 20 years does not correspond to the Universe in which we live. I review recent developments here and quote best fit current values for fundamental cosmological parameters.