FM 01-10; mp_arc 00-??? nlin/CD 0007???
Authors: G. Benfatto, V. Mastropietro
Title: On the density-density critical indices in interacting Fermi systems.
Abstract: The behaviour of correlation functions of $d=1$ interacting fermionic systems is determined by a small number of critical indices. We prove that one of them is exactly zero. As a consequence, the behavior of the Fourier transform of the density-density correlation at zero momentum is qualitatively unaffected by the interaction, contrary to what happens at $\pm 2 \tilde p_F$, if $\tilde p_F$ is the Fermi momentum. The result is obtained by implementing Ward identities in a Renormalization Group approach.
Key words: Critical indices, Ward identities, spin chains.
G.Benfatto, V. Mastropietro
Universita' di Roma 2, Dip. Matematica
Via Fontanile di Carcaricola
00133 Roma, Italia