We consider the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and show that it admits an unique decomposition into dark energy and dark matter components once phantom-like dark energy is excluded. Within this framework, we study structure formation and show that difficulties associated to unphysical oscillations or blow-up in the matter power spectrum c...

For physicists, recent developments in astrophysics and cosmology present exciting challenges. We are conducting “experiments” in energy regimes some of which will be probed by accelerators in the near future, and others which are inevitably the subject of more speculative theoretical investigations. Dark matter is an area where we have hope of making discoveries both with accelerator experimen...

Weak gravitational lensing is rapidly becoming one of the principal probes of dark matter and dark energy in the universe. In this brief review we outline how weak lensing helps determine the structure of dark matter halos, measure the expansion rate of the universe, and distinguish between modified gravity and dark energy explanations for the acceleration of the universe. We also discuss requi...

Spectroscopic methods allow to measure energy differences with unrivaled precision. In the case of gravity resonance spectroscopy, different gravitational states are measured without recourse electromagnetic interaction. This provides a very pure and background free look at gravitation topics related central problem dark matter short distances. this article we analyse effect additional scalar s...