Heavy Quarks and Quarkonia in Thermal ${\rm aAdS}_5$

I review how heavy quarks loose energy in AdS/CFT. I further show how the quantum mechanics of a string in ${\rm aAdS}_5$ together with Kruskal structure of AdS black holes gives rise to the expected stochastic dynamics of a quasi-particle in a thermal bath. The Kruskal structure is needed to reproduce the dynamics of the quasi-particle on the Schwinger-Keldysh contour. After initially considering a particle at rest I extend the results to quarks moving with finite velocity. With the stochastic dynamics of a fast quark clarified, I compute the rate of induced photon bremsthralung associated with the fast heavy quark and compare the results to perturbation theory. Finally I compute the drag of heavy quarkonia in AdS/CFT and discuss the relevance of these results to heavy ion collisions.