Progress report for a research program in theoretical high-energy physics. [Dept. of Physics, Brown Univ]

The past year's research has dealt with a wide range of topics in High-Energy Theoretical Physics. Important new results have been found in the fields of large-N expansions in quantum field theories via an effective Hamiltonian technique, and by the method of classical field equations supplemented by quantum boundary conditions; finite lattice QCD at N/sub c/ = infinity; neutrino oscillations and natural flavor conservation in gauge theory; the vanishing of the renormalized effective potential in phi/sub 4//sup 4/ theory; a new method for treating singular differential equations; and an infrared cluster expansion in quantum field theory. In addition, substantial progress has been made in the analyses of lattice gauge theories; studies of factorization properties of mass and infrared singularities in QCD: non-hermitian quantum problems in the context of Gribov field theories; symmetry breaking via contracted groups; the calculation of Cabibbo-type angles and grand unification theories; and strong-coupling methods in gauge and nongauge field theories, using a systematic, lattice-formulated, perturbation theory, and by the extraction of relevant infrared structure