HIGH-TEMPERATURE SERIES EXPANSIONS FOR ISING-LIKE SYSTEMS ON FRACTALS

High-temperature series expansions up to 16th order for the Ising mode l susceptibility and for the second moment of the correlation function are generated for fractal lattices of the Sierpinski carpet family. T he critical temperature and the critical exponents gamma and nu are ob tained from the series analysis method of differential approximants. F rom our results, we test the validity of estimates previously obtained in the literature and examine the effect of lacunarity on gamma and n u. For carpets with the same fractal dimension, we found that nu decre ases as lacunarity decreases.