MPEJ Volume 2, No.1, 43pp
Received: June 14, 1995, Revised: January 15, 1996, Accepted: January 26, 1996
Federico Bonetto, Vieri Mastropietro
Filled band Fermi systems
ABSTRACT: Extending the result in (B.M.) on one dimensional interacting fermions
in a periodic potential we study the infrared behaviour of the two points
Schwinger function in the filled band case. If the fermions are spinless such
behaviour is completely determined and it depends on the ratio between the
amplitude of the gap and the strength of the interaction. If the ratio is
large the Schwinger function behaviour is similar to the one in the free
non interacting case while if it is small the Schwinger function is deeply
modified and it depends on two anomaly indices, in term of which the occupation
number discontinuity and the spectral gap are expressed. A heuristic second
order analysis of the spinning case is also performed.