Yacine Ali-Haimoud (NYU) “Hunting for Dark Matter in the Early Universe”

It is now well established that the dominant part of non-relativistic matter in the Universe is some substance which appears to be oblivious to any force but gravity. The nature of this dark matter remains a nagging puzzle, and several candidates remain in the running. For instance, dark matter might be a new particle, as light as an electron, which might weakly interact with standard particles. Or it could be partly made of primordial black holes as massive as many Suns, born in the very early Universe from the gravitational collapse of enhanced primordial fluctuations. In this talk, I will describe how one can try and tease out some of the properties of dark matter from the Cosmic Microwave Background (CMB), both through its frequency spectrum, and its angular fluctuations. After reviewing the basic physics underlying the CMB, I will highlight how it can constrain interacting particles and primordial black holes. If time allows, I will discuss what LIGO may be able to tell us about primordial-black holes.