Precision observational cosmology is a powerful tool to progress in the understanding of fundamental issues. It has also shown its capability to unveil new and unexpected properties of the Universe. The nature of Dark Matter and Dark Energy are fundamental questions. Their distribution, equation of state and evolution put constraints on the initial conditions of our Universe, on its geometry, and on the evolution of the large-scale structure distribution. All these scientific issues are well within the scientific perimeter of IN2P3 and most within that of INSU.
LSST is one of the major upcoming projects to reach unprecedented precision on cosmological parameters, combining several probes with many uncorrelated systematics which are expected to largely cancel out. IN2P3 is giving a high priority and support to this programme, both for hardware and software contributions.
LSST-France is involved in the development of three of these probes : supernovae, weak lensing and baryon acoustic oscillations. At LUPM, we intend to focus on the latter one, and to join the software effort of our colleagues. The contacts and preliminary works which have already been achieved have been welcome and considered as worthy both by our French and American colleagues.
We thus propose that the LUPM join LSST, one of the most exciting current projects in observational cosmology. LSST will indeed provide a superb multi-purpose instrument and will enable a new approach for understanding the Dark Matter/Dark Energy puzzle, which has been a continuous activity in LUPM with studies around large scale structures, cluster observations, phenomenological studies on the nature of Dark Matter, and indirect searches for a signal of Dark Matter annihilation in the gamma-ray sky. In our view, it will widen the scientific scope of the LUPM , and open new opportunities for regional collaborations within the OCEVU Labex.
We have taken a great care regarding the technical feasibility of our contribution, taking advantage of local know-how, while not interfering with already started projects. While ambitious, we believe that our program is realistic, and we have made sure to have it validated it by the French project leader and involved international scientists.