2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/156565The first part of these lectures contains an introductory review of the AdS/CFT duality and of its tests. Applications to thermal gauge theory are also discussed briefly. The second part is devoted to a review of gauge-string dualities based on various warped conifold backgrounds, and to their cosmological applications.44 pages. Lectures delivered by I.R.K. at the Les Houches 2007 summer school ``String Theory and the Real World''High Energy Physics - Theorytext