For the Keldysh-Kopaev and the Mattis-Langer models the complete phase diagram (T,μ) is characterized. The degree of criticality of the electron-hole pairing fluctuation operator is obtained as a function of the degree of doping.

We consider the neural network model (Miyashita, 1988. Griniasty et al., 1993) proposed to describe neurophysiological experiments in which structurally uncorrelated patterns are converted into spatially correlated attractors. For such a network of N neurons and for values of the coupling...