We consider del phi interface model on a hard wall. The hydrodynamic large-
scale space-time limit for this model is discussed with periodic boundary b
y Funaki et al. (2000, preprint). This paper studies fluctuations of the he
ight variables around the hydrodynamic limit in equilibrium in one dimensio
n imposing Dirichlet boundary conditions. The fluctuation is non-Gaussian w
hen the macroscopic interface is attached to the wall, while it is asymptot
ically Gaussian when the macroscopic interface stays away from the wall. Ou
r basic method is the penalization, Namely we substitute in the dynamics th
e reflection at the wall by strong drift for the interface when it goes dow
n beyond the wall and show the fluctuation result for such massive del phi
interface model. Then, this is applied to prove the fluctuation for the del
phi interface model on the wall. (C) 2001 Elsevier Science B.V. All rights
reserved.