Abstract:
We briefly describe the theory of root transfer matrices for four-line
models with the field in the new indexless form. We use theoretical and
numerical methods to reveal new effects in the theory of singular points and
phase transitions. A substantial part of the results is obtained using
a numerical algorithm that drastically {(}at least exponentially{\rm)}
reduces the computational complexity of Ising-type models by using
the extremely sparse root transfer matrix.
Keywords:
Ising model, transfer matrix, partition function, ferromagnet, antiferromagnet, free energy, magnetization, magnetic susceptibility, critical point, singular curve, phase transition.
Citation:
V. V. Katrakhov, Yu. N. Kharchenko, “Two-dimensional four-line models of the Ising model type”, TMF, 149:2 (2006), 281–298; Theoret. and Math. Phys., 149:2 (2006), 1545–1558