Critical Wetting with Short-Range Forces: Is Mean-Field Theory Valid?

Critical and tricritical wetting transitions are studied in a simple-cubic nearest-neighbor Ising model. The magnetization m₁ in the surface layer and the susceptibilities χ₁₁=∂m₁∂H₁ and χ₁=∂m₁∂H, where H₁ is the surface field and H the bulk field, are calculated by use of Monte Carlo methods. The critical behavior of these quantities is found to be consistent with simple mean-field behavior; the singularities predicted by various renormalization-group treatments are not observed.