 96627 Armando G. M. Neves
 Renormalization group around a sphere for interacting fermion systems in d>1
(109K, LaTeX plus 6 appended eps figures, see instructions in the file)
Nov 25, 96

Abstract ,
Paper (src),
View paper
(auto. generated ps),
Index
of related papers

Abstract. We will sketch, see the companion paper "Perturbation theory for the
Fermi liquids in d>1" for full details, a momentumspace renormalization
group approach suited to a firstprinciples analysis, in perturbation theory,
of interacting Fermi systems in more than one dimension. Our techniques
are a momentumspace version of the ones introduced by Benfatto and Gallavotti
cite{bg}, \cite{pr}, incorporating some important ideas by Shankar \cite{s}. A
central role is played by bounds on contributions of certain Feynman graphs,
substantially improving power counting ones. These bounds implement the
important idea that renormalization is to be done around a surface in momentum
space, rather than around a point, as usual. As a consequence of the improved
bounds we can simplify the beta functional. Despite simplifications, the beta
functional is still complicated and we cannot yet prove normality (Fermi
liquid) or anomaly (nonFermi liquid) of the system, but we think the formalism
is a good starting point for further simplifications or numerical work.
 Files:
96627.tex