NONPERTURBATIVE EFFECTS IN NONCRITICAL STRINGS WITH SOLITON BACKGROUNDS

We explicitly construct soliton operators in D < 2 (or c < 1) string t heory, and show that the Schwinger-Dyson equations allow solutions wit h these solitons as backgrounds. The dominant contributions from 1-sol iton background are explicitly evaluated in the weak coupling limit, a nd shown to agree with the nonperturbative analysis of string equation s. We suggest that fermions should be treated as fundamental dynamical variables since both macroscopic loops and solitons are constructed i n their bilinear forms. (C) 1997 Elsevier Science B.V.