2ND-ORDER PHASE-TRANSITIONS - FROM INFINITE TO FINITE SYSTEMS

We investigate the Equation of State (EOS) of classical systems having 300 and 512 particles confined in a box with periodic boundary condit ions, We show that such a system, independently on the number of parti cles investigated, has a critical density of about 1/3 the ground stat e density and a critical temperature of about 2.5 MeV, The mass distri bution at the critical point exhibits a power law with tau = 2.23. Mak ing use of the grand partition function of Fisher's droplet model, we obtain an analytical EOS around the critical point in good agreement w ith the one extracted from the numerical simulations.