Partition function zeros for the two-dimensional Ising model III

Complex temperature zeros are calculated numerically from a polynomial form of the partition function of the two-dimensional Ising model in the absence of a magnetic field. In terms of a suitably chosen variable, z, the distribution of zeros is symmetrical under reflection in both the real and imaginary axes. The numerical results confirm the analytical theory in the neighbourhood of the critical point(s), and extend into the complex plane, permitting an analysis of the symmetries of zero distribution for a variety of selected cases of interaction ratios.