SHELL MODELS MODELOS DE CAPAS FIELD THEORIES NUCLEAR THEORY TEORIA NUCLEAR FERMIONES FUNCIONES DE ONDA TEORIAS CAMPO WAVE FUNCTIONS ACOPLAMEINTO COUPLING ESTADOS FUNDAMENTALES GROUND STATES MODELO PARTICULA-HUECO PAIRING INTERACTIONS PARTICLE-HOLE MODEL PARTICLES PARTICULAS PAULI PRINCIPLE PRINCIPIO DE PAULI A Reformulation of the Mode-Goupling Method A graphical procedure to evaluate the many-body shell-model equations Applications of the nuclear field theory to monopole interactions wich include all the vertices of a general force BISMUTO 209* CARBON 14 REACTIONS CHARGE-EXCHANGE REACTIONS CLUSTERS COLLECTIVE MODEL CROSS SECTIONS Cluster of nucleons as elementary modes of excitation in nuclei