This award supports cooperative research in relativity between Ezra Newman, Jeffrey Winicour and others in the physics department at the University of Pittsburgh and Reinaldo Gleiser, Victor Hamity and Carlos Kozameh, all of the Faculty of Mathematics, Astronomy and Physics of the National University of Cordoba, Argentina. They will study four areas in general relativity: global structure of gravitational fields, Yang-Mills theory (the holonomic operator and soluble groups), techniques for the generation of solutions to the Einstein equations and finally, a numerical investigation of general relativity for comparison with analytic solutions of the full Einstein equation. The cooperation between these two institutions began in 1980 and has since grown steadily and has led to several highly regarded joint papers. This formal collaboration will further strengthen that relationship.