High-temperature expansion of the magnetic susceptibility and higher moments of the correlation function for the two-dimensional XY model

We calculate the high-temperature series of the magnetic susceptibility and the second and fourth moments of the correlation function for the XY model on the square lattice to order beta(33) by applying the improved algorithm of the finite lattice method. The long series allow us to estimate the inverse critical temperature as beta(c) = 1.1200(1), which is consistent with the most precise value given previously by the Monte Carlo simulation. The critical exponent for the multiplicative logarithmic correction is evaluated to be theta = 0.054(10), which is consistent with the renormalization group prediction of theta = 1/16.