How to measure Functional RG fixed-point functions for dynamics and at
depinning
Pierre Le Doussal, Kay Jörg Wiese
CNRS-Laboratoire de Physique Théorique de
l'Ecole Normale Supérieure,
24 rue Lhomond, 75005 Paris, France, and
KITP, University of California at Santa Barbara, Santa Barbara, CA 93106-4030, USA.
Abstract
We show how the renormalized force correlator
Δ(u), the function computed in the functional RG (FRG) field
theory, can be measured directly in numerics and experiments on the
dynamics of elastic manifolds in presence of pinning disorder. For
equilibrium dynamics we recover the relation obtained recently in the
statics between Δ(u) and a physical observable. Its extension to
depinning reveals interesting relations to stick-slip models of
avalanches used in dry friction and earthquake dynamics. The particle
limit (d=0) is solved for illustration: Δ(u)
exhibits a cusp and differs from the statics. We propose that the FRG
functions be measured in wetting and magnetic interfaces experiments.
cond-mat/0610525 [pdf]
EPL 77 (2007) 66001 [pdf]
Copyright (C) by Kay Wiese. Last edited March 17, 2008.