Institute for Advanced Study/Princeton University Joint Astrophysics Colloquium

Dark matter constitutes more than 5/6 of the matter in the universe, but its nature and interactions remain one of the great puzzles of fundamental physics. Dark matter collisions or decays, occurring throughout the universe's past, have the potential to produce high-energy particles; such particles may already have reshaped the history of our cosmos, leaving traces of their existence in ionization and heating of the intergalactic medium. I will discuss possible signatures of new dark matter physics in cosmological observations, from the cosmic dark ages to the epoch of reionization, and future directions in both theory and observation.