Journal of Physics A Mathematical and General
Cluster expansions in the (2+1)D Ising model
Chris J. Hamer, A.C. Irving
Abstract
The cluster expansion methods of Nickel are applied to calculate high-temperature series for the vacuum energy and specific heat, the susceptibility, and the mass gap in the (2+1)D Ising model. Critical points and critical exponents are estimated for the square and triangular lattices. The results demonstrate universality with the 3D Ising model, within errors. Exact linked cluster expansions are formulated for the quantities above, and their convergence and scaling properties are investigated.