High-temperature expansions through order 24 for the two-dimensional classical XY model on the square lattice

TL;DR

This paper extends the high-temperature expansion of the 2D classical XY model on a square lattice up to order 24 to refine estimates of its critical parameters.

Contribution

The authors extend the high-temperature series to order 24, providing more accurate data for analyzing the model's critical behavior.

Findings

Extended series improves critical parameter estimates.

Enhanced understanding of phase transition in the XY model.

Refined numerical data for theoretical analysis.

Abstract

The high-temperature expansion of the spin-spin correlation function of the two-dimensional classical XY (planar rotator) model on the square lattice is extended by three terms, from order 21 through order 24, and analyzed to improve the estimates of the critical parameters.