2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/187372We review recent progress in applying the AdS/CFT correspondence to finite-temperature field theory. In particular, we show how the hydrodynamic behavior of field theory is reflected in the low-momentum limit of correlation functions computed through a real-time AdS/CFT prescription, which we formulate. We also show how the hydrodynamic modes in field theory correspond to the low-lying quasinormal modes of the AdS black p-brane metric. We provide a proof of the universality of the viscosity/entropy ratio within a class of theories with gravity duals and formulate a viscosity bound conjecture. Possible implications for real systems are mentioned.23 pages, a review. New proof of the universality of the viscosity entropy ratio, new derivation of Kubo's formula; references added and minor typos corrected in version 2High Energy Physics - Theorytext