2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52474In the first lecture we review the current status of local supersymmetry. In the second lecture we focus on D=11 supergravity as the low-energy limit of M-theory and pose the questions: (1) What are the D=11 symmetries? (2) How many supersymmetries can M-theory vacua preserve?42 pages, latex. Minor corrections; added referencesHigh Energy Physics - TheoryGeneral Relativity and Quantum CosmologyHigh Energy Physics - Phenomenologytext