Raghu Mahajan, Princeton

Hawking showed in 1974 that, once quantum mechanics is taken into consideration, black holes emit a blackbody spectrum of particles. This leads to the celebrated information paradox, which has evaded a completely satisfactory explanation to date. This topic involves a confluence of a lot of rich concepts in physics: general relativity (horizons and singularities), quantum physics (entanglement and unitarity), quantum field theory (microcausality and locality),  and statistical physics (entropy and the second law of thermodynamics). In this talk, I will try to give a clear intuitive picture of all these concepts and how they come together to create the mystery shrouding quantum black holes. There is a deep tension between fundamental physical principles (‘axioms’, one might say), all of which we hold dear. Unfortunately, we have no option but to give up one of these ‘axioms.’ Time permitting, I will try to argue that it is the microcausality principle that must be given up.