DYNAMICAL GAUGE SYMMETRY BREAKING ON COMPACTIFIED SPACETIMES Choon-Lin Ho Institute of Physics, Academia Sinica Taipei, Taiwan 11529, Republic of China We review the essence of dynamical gauge symmetry breaking by Wilson lines in SU(N) gauge theories defined on spacetime manifolds

It is now a well known fact that in a gauge the­ ory on a multiply-connected space, non-integrable phases of Wilson line integrals will give rise to many interesting dynamical effects. 1 ~ 5 For instance, they lead to 0-vacuum in QED on a circle. They also in­ duce a quantization condition for the Chern-Simons term in non-trivial two-dimensional. Last but not least, they cause dynamical gauge symmetry break­ ing and/or mass generation in non-abelian gauge theory. ~ 3 ' 7 TM 1 0 This mechanism has been employed in recent years in superstring phenomenology. 1 1 ' 1 2 In this talk we focus on this last aspect of the dy­ namics of non-integrable phases.