ORDER-PARAMETER PROFILES AND CASIMIR AMPLITUDES IN CRITICAL SLABS

A critical phase confined between two parallel plates, with symmetry-b reaking fields hi and hz acting on each plate, is considered for (i) h (1)h(2) > 0 (denoted nb = ++) and (ii) h(1)h(2) < 0 (ab = +-). Using l ocal-functional methods, we calculate order-parameter scaling function s Psi(ab)(x) and Casimir amplitudes A(ab), for general dimension d. At d = 2, our Psi(++)(x) almost coincides with exact conformal predictio ns. For the Ising universality class, we obtain expansions for A(ab) i n epsilon = 4 - d down arrow 0 in excellent agreement with those obtai ned from field theory and, in d = 3, new results are presented for A(a b) and Psi(ab)(x). [S0031-9007(98)07753-9].