arXiv:cond-mat/0009059 · Physical Review Letters
Critical Behavior of the Two-Dimensional Ising Susceptibility
William P. Orrick, Bernie G. Nickel, Anthony John Guttmann, Jacques H. H. Perk
Abstract
We report computations of the short- and long-distance (scaling) contributions to the square-lattice Ising susceptibility. Both computations rely on summation of correlation functions, obtained using nonlinear partial difference equations. In terms of a temperature variable $\ensuremath{\tau}$, linear in ${T/T}_{c}\ensuremath{-}1$, the short-distance terms have the form ${\ensuremath{\tau}}^{p}(\mathrm{ln}|\ensuremath{\tau}|{)}^{q}$ with $p\ensuremath{\ge}{q}^{2}$. A high- and low-temperature series of $N\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}323$ terms, generated using an algorithm of complexity $\mathrm{O}({N}^{6})$, are analyzed to obtain the scaling part, which when divided by the leading $|\ensuremath{\tau}{|}^{\ensuremath{-}7/4}$ singularity contains only integer powers of $\ensuremath{\tau}$. Contributions of distinct irrelevant variables are identified and quantified at leading orders $|\ensuremath{\tau}{|}^{9/4}$ and $|\ensuremath{\tau}{|}^{17/4}$.