THE VERTICALITY OF THE FERROMAGNETIC-SPIN GLASS PHASE-BOUNDARY OF THE +/- J ISING-MODEL IN THE P-T PLANE

Assuming an appropriate condition, the verticality of the ferromagnetic-spin glass phase boundary of the +/- J Ising model in the p-T plane (p is the concentration of + J bonds: T is the temperature) has been proved rigorously, where the lattice structure containing the dimension of the lattice and the range of the interactions are arbitrary. Further, the existence of a spin glass phase in the p-T plane has been proved for a class of the +/- J Ising models (which are defined in this paper) without any assumption.