Departures from the flat-LCDM model can occur in the geometry, expansion history and the growth of structure. In addition, the relationship between the non-relativistic matter distribution and metric perturbations depends on the theory of gravity and any additional fields that are present. This provides another means of distinguishing the alternatives to LCDM. I will briefly discuss kinematic constraints on the expansion history. I will then concentrate on our attempt to develop a framework for probing the matter-metric relationship on linear, sub-horizon scales in a scale-dependent manner.

On a completely separate topic, (if time permits and there is interest), I will briefly discuss the consequences of relativistic dark matter at the Galactic center for indirect detection signals.