Entropy of a correlated system of nucleons

The self-consistent Greenʹs function method within the ladder approximation allows for a realistic description of strongly interacting quantum many-body systems. At the microscopic level, the single-particle properties of the system are described in terms of finite-width spectral functions. The connection with the bulk properties at finite temperatures can be established via the Luttinger–Ward formalism. An expression for the entropy that includes the effects of the fragmentation of the quasi-particle peak will be presented. The properties of this dynamical quasi-particle entropy will be discussed and the corresponding results will be compared to other approximations. Even though we shall restrict our discussion to nuclear matter, this formalism can be used to study the thermodynamical properties of other fermionic systems.