Energy loss in a strongly coupled thermal medium and the gauge-string duality

We review methods developed in the gauge-string duality to treat energy loss by en- ergetic probes of a strongly coupled thermal medium. After introducing the black holedescription of the thermal medium, we discuss the trailing string behind a heavy quark and the drag force that it implies. We then explain how to solve the linearized Einstein equations in the presence of the trailing string and extract from the solutions the energy density and the Poynting vector of the dual gauge theory. We summarize some efforts to compare these calculations to heavy ion phenomenology.