Universality classes for critical wetting

The systematics of the wetting transition at solid-gas interfaces in systems interacting with inversepower-law potentials is investigated. The correct form of the effective Hamiltonian for $l$, the interfacesubstrate separation, is determined, and it is shown that for a given type of continuous wetting transition (e.g., critical wetting) there are three regimes of critical behavior, depending on the spatial dimension $d$. New results for the critical exponents in the intermediate regime are also presented.