Surface Exponents for a Linear Polymer at the d = 2 Θ-Point

By extending a previous analysis of bulk properties, accurate Monte Carlo enumerations of SAW with attractive n.n. interactions on the square lattice are used to obtain γ 1 t = 0.57 ± 0.09 and γ 11 t = -0.53 ± 0.10 for the entropic boundary exponents at the Θ-point. This gives new indications concerning the possible validity of recent conjectures about the Θ-point universality class. In particular, under plausible assumptions, these results appear compatible with a field-theoretic description in terms of a nonunitary superconformal field theory with central charge c = 1/2, for which γ 1 t = 15/28 and γ 11 t = -4/7 should be expected.