2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/55756This is an expository paper describing the geometry of certain Sasakian-Einstein manifolds. Such manifolds have recently become of interest due to Maldacena's AdS/CFT conjecture. They describe near-horizon geometries of branes at conical singularities.59 pages, to appear in Essays on Einstein Manifolds, M. Wang and C. LeBrun, edsHigh Energy Physics - TheoryDifferential Geometrytext