Numerical investigation of logarithmic corrections in two-dimensional spin models

The analysis of correlation function data obtained by Monte Carlo simulations of the two-dimensional four-state Potts model, XY model, and self-dual disordered Ising model at criticality are presented. We study the logarithmic corrections to the algebraic decay exhibited in these models. A conformal mapping is used to relate the finite-geometry information to that of the infinite plane. Extraction of the leading singularity is altered by the expected logarithmic corrections, and we show numerically that both leading and correction terms are mutually consistent. (C) 2004 MAIK Nauka / Interperiodica.