Interferometric Tests of Wave-Function Collapse

Among the various commonly proposed interpretations of quantum mechanics, models of wave function collapse are unique in being empirically falsifiable. Here we review experiments which place bounds on the parameter space of these models, with a particular focus on matter-wave interferometry. Proving the persistence of superposition states is the most direct way to test collapse models, and by performing interferometry with macromolecules we can exclude large regions of parameter space due to the quadratic scaling of the collapse rate with mass.