2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/101740The fluctuation pressure that an infinitely extended fluid membrane exerts on two enclosing parallel hard walls is computed. Variational perturbation theory is used to extract the hard-wall limit from a perturbative expansion through six loops obtained with a smooth wall potential. Our result alpha=0.0821+/-0.0005 for the constant conventionally parametrizing the pressure lies above earlier Monte Carlo results.9 pages, 1 figure; section III shortened, discussion extended, some minor changesStatistical MechanicsSoft Condensed MatterQuantitative Methodstext