title: Elementary constraints on autocorrelation function scalings.
abstract: Elementary algebraic constraints on the form of an autocorrelation function C(t(w)+tau,t(w)) rule out some two-time scalings found in the literature as possible long-time asymptotic forms. The same argument leads to the realization that two usual definitions of many-time scale relaxation for aging systems are not equivalent.
authors.affiliation: PMMH Ecole Supérieure de Physique et Chimie Industrielles, 10 rue Vauquelin, 75231 Paris CEDEX 05, France.
authors.forename: Jorge
authors.initials: J
authors.lastname: Kurchan