N ov 2 01 3 FRW universe in the laboratory

We consider an expanding relativistic fluid with spherical symmetry as a model for an analog Friedmann-Robertson-Walker (FRW) spacetime. In the framework of relativistic acoustic geometry we demonstrate how to mimic an arbitrary FRW spacetime with positive, zero or negative spatial curvature. In the Lagrangian description we show that a particular FRW spacetime is obtained by choosing the appropriate potential. We discuss several examples and in particular the analog de Sitter spacetime in the coordinate representation with positive and negative spatial curvature.