The systematic approach for the off-perturbative calculations in disordered systems is developed. The proposed scheme is applied for the random temperature and the random field ferromagnetic Ising models. It is shown that away from the critical point, in the paramagnetic phase of the random...

In this work, after a short phenomenological introduction on glasses, I will describe some recent progresses that have been made in glasses using the replica method in the definition and in the evaluation of the configurational entropy (or complexity). These results are at the basis of some...

The mean number (N) of metastable states in higher order short-range spin glasses is estimated analytically using a variational method introduced by Tanaka and Edwards for very large coordination numbers. For lattices with small connectivities, numerical simulations do not show any significant...

We introduce a simple spin model which shows glassy behavior at low temperatures, despite a Hamiltonian which is completely homogeneous and possesses no randomness; ergodicity breaking in this model is due entirely to the model's dynamics. We solve exactly for the model's equilibrium partition...

The ±J Ising spin glass [probabilities p and (1−p) associated with ferromagnetic and antiferromagnetic couplings, respectively] is studied, at zero temperature, on a hierarchical lattice that approaches the square lattice. It is shown that, for a wide range of values of p [between (1−pc)...

Based on a recently developed algorithm for the exploration of ground states in bond-diluted lattice spin glasses, we determine the scaling of defect energies with system size for Ising spin glasses at the bond percolation threshold pc. The results can be related by well-known scaling relations...

We present some calculations for the thermodynamic behavior of mean-field ferromagnetic p-spin interaction models in the presence of quenched random fields. For both Ising and spherical spin variables, we use the law of large numbers, without recourse to the replica trick, to obtain a...

We present results of the non-linear dynamic susceptibility χ(t) in a mean field Potts glass from simulations in a wide range of temperatures above the theoretically predicted dynamical transition, for various system sizes up to 2560 spins. χ(t) has a maximum, with a height that diverges like...