Partition function for two-dimensional nearest neighbour Ising model in the presence of external magnetic field

Abstract

The partition function for two-dimensional nearest neighbour Ising models in the presence of a magnetic field is derived . A comparison with the partition functions predicted by Onsager is carried out. The critical temperature estimated by two different methods yields good agreement with the result of Yang and Lee.

arXiv comment4 pages;one Figure; References added to the earlier version