ar X iv : a st ro - p h / 02 10 09 1 v 1 3 O ct 2 00 2 Wide - field cosmic shear surveys

ar X iv : a st ro - p h / 02 10 09 3 v 1 3 O ct 2 00 2 Prospects for weak lensing / cosmic shear with VLTs

The present status of weak lensing analyses of clusters of galaxies and of cosmic shear surveys are presented and discussed. We focus on the impact of very large telescopes on present-day and future surveys and compare their potential with HST or wide field 4 meter telescopes.

ar X iv : a st ro - p h / 02 10 42 8 v 1 1 8 O ct 2 00 2 Star Clusters in Interacting Galaxies : The Case of M 51 Nate

ar X iv : a st ro - p h / 02 12 56 6 v 1 3 0 D ec 2 00 2 Dark Energy : Is it Q or Λ ?

New observations of Cosmic Microwave Background Anisotropies, Su-pernovae luminosity distances and Galaxy Clustering are sharpening our knowledge about dark energy. Here we present the latest constraints.

ar X iv : a st ro - p h / 02 10 04 2 v 1 1 O ct 2 00 2 Variable Speed of Light Theories

Two variable speed of light models and their physical consequences are investigated. Talk given at the workshop on varying fundamental constants, JENAM 2002, Porto, Portugal, September 2-7, 2002. To be published in the proceedings by Kluwer publications. 1. Varying Speed of Light Cosmology: An Alternative to In-

ar X iv : a st ro - p h / 04 10 41 3 v 1 1 8 O ct 2 00 4 Quantum - Gravity phenomenology and high energy particle propagation

Quantum-gravity effects may introduce relevant consequences for the propagation and interaction of high energy cosmic rays particles. Assuming the space-time foamy structure results in an intrinsic uncertainty of energy and momentum of particles, we show how low energy (under GZK) observations can provide strong constraints on the role of the fluctuating space-time structure.