Critical temperature of (d+1)-dimensional Ising films

An alternative approach is proposed to treat the critical point for general Ising spin systems. From the analytic properties of the free energy, we are in principle able to calculate analytically the critical temperature Tc(l) for (d+1)-dimensional Ising films to any order cumulant as a function of the number l of hyperlayers in the hyperfilm. Explicit expressions up to the fourth order are given. It is shown from the general expression for Tc(m)(l) that [Tc(l)-Tc]/Tc=b/(l+a) in the limit l→. Comparisons with existing results for d=2 are discussed.