GAUGE INVARIANCE Albedo BCs Application of a modified mean-field method to a gauge-invariant variational calculation Bifurcation (mathematics) Boundary conditions COUPLING EXPANSION Cadena pendiente Calculation of critical pomeron intercept with block-spin methods Diffusion ENERGY SPECTRUM ESPIN Física Global analysis HAMILTONIAN INVARIANCE PRINCIPLES INVARIANZA DE UN PATRON ISING MODEL LIOUVILLE THEOREM MEAN-FIELD THEORY Mathematical models Molecular dynamics Monostable reaction diffusion system Monostable reaction-diffusion Módulo viscoelástico Non-equilibrium potential PARTICULAS DE POMERANCHUK POMERANCHUK PARTICLES Pattern selection Piecewise linear techniques QUANTUM MECHANICS