Why one needs a functional renormalization group to survive in a disordered world
Kay Jörg Wiese
CNRS-Laboratoire de Physique Théorique de
l'Ecole Normale Supérieure,
24 rue Lhomond, 75005 Paris, France
Abstract
In these proceedings, we discuss why
functional renormalization is an essential tool to treat strongly
disordered systems. More specifically, we treat elastic manifolds in a
disordered environment. These are governed by a disorder distribution,
which after a finite renormalization becomes non-analytic, thus
overcoming the predictions of the seemingly exact dimensional
reduction. We discuss how a renormalizable field theory can be
constructed even beyond 2-loop order. We then consider an elastic
manifold embedded in N dimensions, and give the exact solution for N
to infinity. This is compared to predictions of the Gaussian replica
variational ansatz, using replica symmetry breaking. Finally, the
effective action at order 1/N is reported.
cond-mat/0511529 [pdf]
Pramana 64 (2005) 817-827 [pdf]
Copyright (C) by Kay Wiese. Last edited March 17, 2008.