COMPACT GAUGE-THEORIES OF OPEN P-BRANES

We study phase transitions induced by topological defects in compact A belian gauge theories of open p-branes in (d+1) space-time dimensions. Starting from a massive antisymmetric tensor theory for the open p-br anes we show how the condensation of topological defects can lead to a decoupled phase with a massless tensor coupled to closed (p - 1)-bran es and a massive tensor coupled to open (p + 1)-branes. We also consid er the case, relevant in string theory, in which the boundaries of the p-branes are constrained to live on a. Dirichlet n-brane.