INTEGRATION OF THE PARTITION FUNCTION OF THREE-DIMENSIONAL ISING MODEL

George Allen Baker Jr.

Bernd A. Berg, Ulrich H. E. Hansmann, Thomas Neuhaus

SHI HE, Bailin Hao, 中国科学院

A class of approximate interpolation formula for the partition function of the 3-dimensional Ising model is proposed on the basis of a previous analysis of the 2-dim rigorous solution and 3-dim Q-approximation. In principle, the present knowledge about the location of the singular point and the low- and high-temperature expansion coefficients can be incorporated provided a sufficient amount of computation is carried out. One and the same analytical expression leads to good low- and high-temperature behaviour except for the specific heat singularity.

I. R. Yukhnovskii

Nelson A. Alves, J. R. Drugowich de Felício, Ulrich H. E. Hansmann

A general numerical method is presented to locate the partition function zeros in the complex β plane for large lattice sizes. We apply this method to the 2D Ising model and results are reported for square lattice sizes up to L = 64. We also propose an alternative method to evaluate corrections to scaling which relies only on the leading zeros. This method is illustrated with our data.

John Stephenson, Jan Van Aalst