1. Correlations in the nuclear many-body system used to study: a- Microscopic and Bulk Properties of Nuclear matter, b- Response function, c- Neutron Star and Its Constituents and Observables. d- Local Density Approximation. e- Pion Condensation and Particle-Hole interaction 2. Nuclear Structure and nucleon-nucleon forces and how to use it to study bound nuclei as a deuteron nucleus and scattering theory.