Effective field theory for Fermi systems in a large N expansion

摘要

A system of fermions with short-range interactions at finite density is studied using the framework of effective field theory. The effective action formalism for fermions with auxiliary fields leads to a loop expansion in which particle-hole bubbles are resumed to all orders. For spin-independent interactions, the loop expansion is equivalent to a systematic expansion in I IN, where N is the spin-isospin degeneracy g. Numerical results at next-to-leading order are presented and the connection to the Bose limit of this system is elucidated. (C) 2002 Elsevier Science (USA). [References: 43]