HIGH-TEMPERATURE STUDY OF THE KOSTERLITZ-THOULESS PHASE-TRANSITION INTHE XY MODEL ON THE TRIANGULAR LATTICE

High-temperature series expansions of the spin-spin correlation functi on for the XY (or plane rotator) model on the triangular lattice are e xtended by two terms up to order beta14. Tables of the expansion coeff icients are reported for the correlation function spherical moments of order l = 0 and 2. Our analysis of the series supports the Kosterlitz -Thouless predictions on the structure of the critical singularities a nd leads to fairly accurate estimates of the critical parameters.