Speaker
Description
The primordial power spectrum is well constrained on large scales by the CMB and galaxy surveys, but is much harder to probe on small scales, roughly below the scale of galaxy clusters. These small scales are a powerful discriminant between dark matter models: enhanced power there drives the early collapse of compact objects such as ultracompact minihalos, and in more extreme cases primordial black holes. I will describe how their abundance is calculated in different frameworks, and then turn to how they can be detected, either through dark matter annihilation or through their gravitational influence alone. Finally, I will discuss what such detections or constraints tell us about the primordial power spectrum on these otherwise inaccessible scales.