87 research outputs found
Is a "homogeneous" description of dynamic heterogeneities possible?
We study the simplest model of dynamic heterogeneities in glass forming
liquids: one-spin facilitated kinetic Ising model introduced by Fredrickson and
Andersen [G.H. Fredrickson and H.C. Andersen, Phys. Rev. Lett. 53, 1244 (1984);
J. Chem. Phys. 83, 5822 (1985)]. We show that the low-temperature, long-time
behavior of the density autocorrelation function predicted by a scaling
approach can be obtained from a self-consistent mode-coupling-like
approximation.Comment: accepted for publication in the Journal of Chemical Physic
Divergent four-point dynamic density correlation function of a glassy colloidal suspension: a diagrammatic approach
We use a recently derived diagrammatic formulation of the dynamics of
interacting Brownian particles [G. Szamel, J. Chem. Phys. 127, 084515 (2007)]
to study a four-point dynamic density correlation function. We re-sum a class
of diagrams which separate into two disconnected components upon cutting a
single propagator. The resulting formula for the four-point correlation
function can be expressed in terms of three-point functions closely related to
the three-point susceptibility introduced by Biroli et al. [Phys. Rev. Lett.
97, 195701 (2006)] and the standard two-point correlation function. The
four-point function has a structure very similar to that proposed by Berthier
and collaborators [Science 310, 1797 (2005), J. Chem. Phys. 126, 184503
(2007)]. It exhibits a small wave vector divergence at the mode-coupling
transition
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