Shells: Model and theory

摘要: These lectures are devoted to examine the theoretical bases of the Shell Model. We shall be led to reformulate the theory of effective interactions so as to incorporate naturally whatever regularities and simplicity emerge from the data. The importance of linked cluster mechanisms will be stressed, and it will appear that much we learn from the behaviour of the Schrodinger equation in the full Hilbert space can be put to good use in diagonalizing large but finite matrices. This is due to the factorization properties of the amplitudes in the wave-functions which are at the origin of linked cluster theory and make it possible to take advantage of the low rank (I+ 2 body) of the forces to devise accurate truncations. After some preliminary remarks to define the context of these talks, we shall review in Lecture 1 some basic ideas about the shell model, show some of its successes and then examine the difficulties to be overcome in …