Experimental search for a Lorentz invariant spacetime granularity:   Possibilities and bounds
  We consider a search for phenomenological signatures from an hypothetical space-time granularity that respects Lorentz invariance. The model is based on the idea that the metric description of Einstein's gravity corresponds to a hydrodynamic characterization of some deeper underlying structure, and that Einstein's gravity is thus to be seen as emergent. We present the specific phenomenological model in detail and analyze the bounds on its free parameters established by a experiment specifically designed to test this model. 
Pedro Aguilar, Yuri Bonder, Daniel Sudarsky
gr-qc