Wandering of a contact line at thermal equilibrium

We reconsider the problem of the solid-liquid-vapor contact-line on a disor dered substrate, in the collective pinning regime. We perform a replica var iational calculation which confirms the scaling behavior obtained from Lark in-Imry-Ma-like arguments and provides a quantitative prediction for the co rrelation function of the line. This prediction is in good agreement with e xperimental findings for the case of superfluid helium on a caesium substra te. [S1063-651X(99)06307-2].