TYPICAL AND EXCEPTIONAL SHAPE FLUCTUATIONS OF INTERACTING STRINGS

1-dimensional strings governed by a finite tension are studied in d = 1 + d perpendicular-to dimensions. In the presence of a short-ranged attractive interaction, two strings undergo a nontrivial unbinding transition for any value of d perpendicular-to. The characteristic unbinding temperature T* vanishes as 1/d perpendicular-to for large d perpendicular-to. The critical exponents evolve with d perpendicular-to in a singular and nonmonotonic way. For d perpendicular-to < 4, the typical string fluctuations consist of humps with roughness exponent-zeta = 1/2; for d perpendicular-to > 4, on the other hand, these humps become more and more exceptional as the transition is approached and are then governed by a power law distribution.