9421385 Sucher The goal of this research is to understand the fundamental interactions of nature through their manifestations in various aspects of particle physics, astrophysics and atomic physics. In particular, this includes exploration of the nature of new physics such as grand unification, supersymmetry, new gauge symmetries which provide solutions to various unsolved problems of the successful standard model of electroweak interactions, such as the observed fermion mass hierarchies, the strong CP problem etc., and have the potential to explain observations pertaining to neutrino masses and mixings inferred from solar neutrino data and hot dark matter of the universe. Another area of investigation is the application of Quantum Electrodynamics, the quantum theory of electromagnetic interactions and Quantum Chromodynamics, the theory of strong interactions to problems of atomic and particle physics. Specfic examples include the analysis of forces between atoms, ions, and electrons which depend on spin, the understanding of the highly excited states of the helium atom, the interplay between strong and electromagnetic forces in proton-proton scattering, and the computation of forces between quarks and anti-quarks resulting from the exchange of gluons. ***