A local limit theorem for directed polymers in random media : the continuous and the discrete case
A lower bound for the principal eigenvalue of the Stokes operator in a random domain
This article is dedicated to localization of the principal eigenvalue (PE) of the Stokes operator acting on solenoidal vector fields that vanish outside a large random domain modeling the pore space in a cubic block of porous material with disordered micro-structure. Its main result is an asymptotically deterministic lower bound for the PE of the sum of a low compressibility approximation to the Stokes operator and a small scaled random potential term, which is applied to produce a similar bound...
A lower bound for time correlation of lattice gases.
A mathematical model to reproduce the wave field generated by convergent lenses.
A Metropolis adjusted Nosé-Hoover thermostat
We present a Monte Carlo technique for sampling from the canonical distribution in molecular dynamics. The method is built upon the Nosé-Hoover constant temperature formulation and the generalized hybrid Monte Carlo method. In contrast to standard hybrid Monte Carlo methods only the thermostat degree of freedom is stochastically resampled during a Monte Carlo step.
A microscopic model for the Burgers equation and longest increasing subsequences.
A Mixed Formulation of the Monge-Kantorovich Equations
We introduce and analyse a mixed formulation of the Monge-Kantorovich equations, which express optimality conditions for the mass transportation problem with cost proportional to distance. Furthermore, we introduce and analyse the finite element approximation of this formulation using the lowest order Raviart-Thomas element. Finally, we present some numerical experiments, where both the optimal transport density and the associated Kantorovich potential are computed for a coupling problem and problems...
A model of a radially symmetric cloud of self-attracting particles
We consider a parabolic equation which describes the gravitational interaction of particles. Existence of solutions and their convergence to stationary states are studied.
A model of dense fluids
We obtain coupled reaction-diffusion equations for the density and temperature of a dense fluid, starting from a discrete model in which at most one particle can be present at each site. The model is constructed by the methods of statistical dynamics. We verify that the theory obeys the first and second laws of thermodynamics. Some remarks on measurement theory for the position of a particle are offered.
A model of evolution of temperature and density of ions in an electrolyte
We study existence and nonexistence of solutions (both stationary and evolution) for a parabolic-elliptic system describing the electrodiffusion of ions. In this model the evolution of temperature is also taken into account. For stationary states the existence of an external potential is also assumed.
A model of frontal polymerization including the gel effect.
A monotonicity result for hard-core and Widom-Rowlinson models on certain -dimensional lattices.
A multigrid algorithm for solving the multi-group, anisotropic scattering Boltzmann equation using first-order system least-squares methodology.
A new approach to the problem of removal of soluble gaseous pollutants from the atmosphere and its correspondence with the existing approach.
A new exponentially fitted triangular finite element method for the continuity equations in the drift-diffusion model of semiconductor devices
A new exponentially fitted triangular finite element method for the continuity equations in the drift-diffusion model of semiconductor devices
In this paper we present a novel exponentially fitted finite element method with triangular elements for the decoupled continuity equations in the drift-diffusion model of semiconductor devices. The continuous problem is first formulated as a variational problem using a weighted inner product. A Bubnov-Galerkin finite element method with a set of piecewise exponential basis functions is then proposed. The method is shown to be stable and can be regarded as an extension to two dimensions of the...
A new model for the transport of particles in a thermostatted system.
A new perspective on some approximations used in neutron transport modeling
In this contribution, we will use the Maxwell-Cartesian spherical harmonics (introduced in [1,2]) to derive a system of partial differential equations governing transport of neutrons within an interacting medium. This system forms an alternative to the well known approximation, which is based on the expansion of the directional dependence into tesseral spherical harmonics ([3,p.197]). In comparison with this latter set of equations, the Maxwell-Cartesian system posesses a much more regular structure,...
A new rational free-fermion solution of the Yang-Baxter equation.
A new solution for the director relaxation problem in twisted nematic film based on wavelet analysis.