Four-Dimensional String/String Duality

Abstract

We present supersymmetric soliton solutions of the four-dimensional heterotic string corresponding to monopoles, strings and domain walls. These solutions admit the D = 10 interpretation of a fivebrane wrapped around 5, 4 or 3 of the 6 toroidally compactifìed dimensions and are arguably exact to all orders in α′. The solitonic string solution exhibits an SL(2, Z) strong/weak coupling duality which however corresponds to an SL(2, Z) target space duality of the fundamental string.

Talk given by MJD. Work supported in part by NSF grant PHY-9106593.

Supported by a World Laboratory Fellowship.