Violation of finite-size scaling in the spherical limit of the ρ4 theory

We derive exact results of thermodynamic quantities of the O(n) symmetric phi(4) theory in the limit n --> infinity both for the bulk with external field h and in a finite d-dimensional hypercubic geometry with periodic boundary conditions at h = 0. Universal bulk scaling is verified in the asymptotic region of the h-T plane. For the finite system, however, we show that finite-size scaling is violated in the region L >> zeta where L is the size of system and zeta is the bulk correlation length above T-c. (C) 2000 Elsevier Science B.V. All rights reserved.