1,168 research outputs found
Mode-coupling theory of sheared dense granular liquids
Mode-coupling theory (MCT) of sheared dense granular liquids %in the vicinity
of jamming transition is formulated. Starting from the Liouville equation of
granular particles, the generalized Langevin equation is derived with the aid
of the projection operator technique. The MCT equation for the density
correlation function obtained from the generalized Langevin equation is almost
equivalent to MCT equation for elastic particles under the shear. It is found
that there should be the plateau in the density correlation function.Comment: 22 pages, 2 figure. to be published in Progress of Theoretical
Physics. to be published in Progress of Theoretical Physic
Nonequilibrium identities of granular vibrating beds
We derive the integral fluctuation theorem around a nonequilibrium stationary
state for frictionless and soft core granular particles under an external
vibration achieved by a balance between an external vibration and inelastic
collisions. We also discuss the connection between the integral fluctuation
theorem and the generalized Green-Kubo formula.Comment: 15 pages, no figures to be published in Comptes rendus - M\'ecanique
as Proceedings of EuroMech2012 at Graz, Austri
Nonequilibrium liquid theory for sheared granular liquids
A noneqilibrium liquid theory for uniformly sheared granular liquids is
developed starting from the SLLOD Liouville equation. We derive a generalized
Green-Kubo formula and also demonstrate that the formulation is essentially
independent of the choice of initial condition.Comment: 12 pages, 2 figure
Spatial correlations in sheared isothermal liquids : From elastic particles to granular particles
Spatial correlations for sheared isothermal elastic liquids and granular
liquids are theoretically investigated. Using the generalized fluctuating
hydrodynamics, correlation functions for both the microscopic scale and the
macroscopic scale are obtained. The existence of the long-range correlation
functions obeying power laws has been confirmed. The validity of our
theoretical predictions have been verified from the molecular dynamics
simulation.Comment: 34 pages, 12 figure
Slow nonequilibrium dynamics: parallels between classical and quantum glasses and gently driven systems
We review an scenario for the non-equilibrium dynamics of glassy systems that
has been motivated by the exact solution of simple models. This approach allows
one to set on firmer grounds well-known phenomenological theories. The old
ideas of entropy crisis, fictive temperatures, free-volume... have clear
definitions within these models. Aging effects in the glass phase are also
captured. One of the salient features of the analytic solution, the breakdown
of the fluctuation-dissipation relations, provides a definition of a bonafide
{\it effective temperature} that is measurable by a thermometer, controls heat
flows, partial equilibrations, and the reaction to the external injection of
heat. The effective temperature is an extremely robust concept that appears in
non-equilibrium systems in the limit of small entropy production as, for
instance, sheared fluids, glasses at low temperatures when quantum fluctuations
are relevant, tapped or vibrated granular matter, etc. The emerging scenario is
one of partial equilibrations, in which glassy systems arrange their internal
degrees of freedom so that the slow ones select their own effective
temperatures. It has been proven to be consistent within any perturbative
resummation scheme (mode coupling, etc) and it can be challenged by
experimental and numerical tests, some of which it has already passed.Comment: 15 pages, 8 figure
The effective temperature
This review presents the effective temperature notion as defined from the
deviations from the equilibrium fluctuation-dissipation theorem in out of
equilibrium systems with slow dynamics. The thermodynamic meaning of this
quantity is discussed in detail. Analytic, numeric and experimental
measurements are surveyed. Open issues are mentioned.Comment: 58 page
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