ENHANCED SYMMETRIES AND THE GROUND-STATE OF STRING THEORY

The ground state of string theory may Lie at a point of ''maximally en hanced symmetry'', at which all of the moduli transform under continuo us or discrete symmetries. This hypothesis, along with the hypotheses that the theory at high energies has N = 1 supersymmetry and that the gauge couplings are weak and unified, has definite consequences for lo w energy physics. We describe these, and offer some suggestions as to how these assumptions might be compatible. (C) 1998 Elsevier Science B .V. All rights reserved.