A quasi resonant laser induces a long-range attractive force within a cloudView original: http://arxiv.org/abs/1202.1258
of cold atoms. We take advantage of this force to build in the lab quasi 1D
systems of particles with a gravitational-like interaction, at a fluid level of
modeling. We give experimental evidences of such an interaction in a Strontium
cold gas, studying the density profile of the cloud, its size as a function of
the number of atoms and its breathing oscillations.