EINSTEIN-YANG-MILLS THEORY WITH A MASSIVE DILATON AND AXION - STRING-INSPIRED REGULAR AND BLACK-HOLE SOLUTIONS

We study the classical theory of a non-Abelian gauge field [gauge grou p SU(2)] coupled to a massive dilaton, massive axion, and Einstein gra vity. The theory is inspired by the bosonic part of the low-energy het erotic string action for a general Yang-Mills field, which we consider to leading order after compactification to 3 + 1 dimensions. We impos e the condition that spacetime be static and spherically symmetric, an d we introduce masses via a dilaton-axion potential associated with su persymmetry breaking by gaugino condensation in the hidden sector. In the course of describing the possible non-Abelian solutions of the sim plified theory, we consider in detail two candidates: a massive dilato n coupled to a purely magnetic Yang-Mills field, and a massive axion f ield coupled to a non-Abelian dyonic configuration, in which the elect ric and magnetic fields decay too rapidly to correspond to any global gauge charge. We discuss the feasibility of solutions with and without a nontrivial dilaton for the latter case, and present numerical regul ar and black hole solutions for the former.