In this paper we solve the problem of describing all nonlocal Hamiltonian operators of hydrodynamic type with flat metrics and establish that this nontrivial special class of Hamiltonian operators is closely connected with the associativity equations of twodimensional topological quantum field theories and the theory of Frobenius manifolds. It is shown that the Hamiltonian operators of this cla...

The most general description of the classical world is in terms of local densities (such as number, momentum, energy), and these typically evolve according to evolution equations of hydrodynamic form. To explain the emergent classicality of these variables from an underlying quantum theory, it is therefore necessary to show, firstly, that these variables exhibit negligible interference, and sec...

A finite difference upwind discretization scheme in two dimensions is presented in detail for the transient simulation of the highly coupled non-linear partial differential equations of the full hydrodynamic model, providing thereby a practical engineering tool for improved charge carrier transport simulations at high electric fields and frequencies. The discretization scheme preserves the cons...

The Chapman-Enskog method of solution of kinetic equations, such as the Boltzmann equation, is based on an expansion in gradients of the deviations of the hydrodynamic fields from a uniform reference state (e.g., local equilibrium). This paper presents an extension of the method so as to allow for expansions about arbitrary, far-from-equilibrium reference states. The primary result is a set of ...

We consider a dilute gas of hard spheres in dimension d> or =2 that upon collision either annihilate with probability p or undergo an elastic scattering with probability 1-p . For such a system neither mass, momentum, nor kinetic energy is a conserved quantity. We establish the hydrodynamic equations from the Boltzmann equation description. Within the Chapman-Enskog scheme, we determine the tra...

Recent progress on the derivation of macroscopic quantum models is reviewed. The first part of the survey is concerned with collisionless models, namely quantum hydrodynamic equations. These models are derived from the mixed-state Schrödinger system or from the Wigner equation. In the second part, starting from a Wigner-Boltzmann-type equation, quantum diffusion models like the viscous quantum ...

P.-A. Hervieux and G. Manfredi∗ Institut de Physique et Chimie des Matériaux de Strasbourg, BP 43, F-67034 Strasbourg, France (Dated: September 8, 2008) Abstract A quantum hydrodynamic (fluid) model, derived from the Wigner-Poisson equations, is used to investigate the ultrafast electron dynamics in thin metal films. The hydrodynamic equations, which include exchange and correlation effects, ca...

The BGK model kinetic equation is applied to spatially inhomogeneous states near steady uniform shear flow. The shear rate of the reference steady state can be large so the states considered include those very far from equilibrium. The single particle distribution function is calculated exactly to first order in the deviations of the hydrodynamic field gradients from their values in the referen...

ARTICLE OUTLINE Definition of the Subject and Importance Introduction Granular Matter and its Statistical Mechanics Nonequilibrium statistical mechanics Liouville equation Stationary homogeneous state Macroscopic Balance Equations ”Normal” States and Hydrodynamics Navier-Stokes Approximation Constitutive equations Green-Kubo expressions Hydrodynamic equations Discussion and Outlook Bibliography...