2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/25253Central to our understanding of quantum many particle physics are two ideas due to Landau. The first is the notion of the electron as a well-defined quasiparticle excitation in the many body state. The second is that of the order parameter to distinguish different states of matter. Experiments in a number of correlated materials raise serious suspicions about the general validity of either notion. A growing body of theoretical work has confirmed these suspicions, and explored physics beyond Landau's paradigms. This article provides an overview of some of these theoretical developments.Proceedings of conference on `Recent Progress in Many-Body Theories', Santa Fe, New Mexico (USA), Aug 23-27 (2004)Strongly Correlated Electronstext