Research  Interests PHYSICS OF ELECTRONS: Electron transport in metals, quantum many body theory. Kondo effect, local spin fluctuations, time dependent perturbations in metals. Itinerant electron magnetism, spin fluctuation effects in nearly and weakly ferromagnetic Fermi systems. Strongly correlated electron systems including mixed valent systems, heavy fermions and oxides. Electron localization, quantum interference effects in transport, weak localization. Metal-insulator and superconductor-insulator transitions. High temperature superconductivity (microscopic theory, phenomena in the mixed phase eg flux lattice melting as well as vortex dynamics and quasiparticle transport). Colossal magnetoresistance manganites.  DISORDERED SYSTEMS: Electrons and other waves in random media. Glass transition and the glassy state. Nonequilibrium in random systems. Boson localization. LIQUIDS AND SOLIDS:  Density wave theory of freezing, and of the solid. Relative structural stability of solids. Density functional approach to phenomena in classical condensed systems, eg. dislocations, solid solid interfaces, fracture.  BIOLOGICAL PHYSICS: Fluctuations in cellular processes and their biological consequences; chromatin and transcription; coarse grained approaches to cellular phenomena.