Last news, from the European EDEN meeting on dark Energy
15 Jan, 2006 10:18 am
Last December a conference was organised in Paris to discuss the issue of Dark Energe one of the most puzzeling ingredient of the cosmic budget.
Invoked to account for the acceleration of cosmic expansion that unveiled itself in supernova Hubble diagrams, this new and astonishingly dominant ingredient of the cosmic budget remains, since its observational discovery in 1997, a complete mystery.
Indeed, the nature of Dark Energy and its possible evolution in time are still totally unknown, and cosmologists are left with three theoretical explanations. The acceleration of expansion could be due to a cosmological constant (the favoured, though problematic, option), to a scalar field of various possible degrees of complexity, or to a subtle modification of the laws of gravity.
At the Laboratoire de Physique Nucleaire et de Hautes Energies of the Jussieu Campus, the cosmologists discussed the possible interpretations of current data, the various Dark Energy models, and their predicted effects on the observed universe. The most recent results from the SDSS galaxy survey and the CFHT Legacy Survey were presented. Researchers reviewed the different observational tests (provided by supernovae, weak gravitational lensing, baryon oscillations and galaxy clusters) that have to be applied and combined in order to disentangle all the possibilities. Systematic effects and intrinsic limitations of each cosmological probe were also discussed in detail.
The conference revealed that space borne (like SNAP and DUNE) and ground based (like DarkCam, Pan-Starrs) projects are flourishing all around the globe, with the specific aim of shedding light on Dark Energy. The next few years will definitely be very exciting times for cosmology,from both the theory and the observation sides.