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Related papers: Diffusion laws select boundary conditions

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Multiscale modelling aims to systematically construct macroscale models of materials with fine microscale structure. However, macroscale boundary conditions are typically not systematically derived, but rely on heuristic arguments,…

Dynamical Systems · Mathematics 2019-11-18 Chen Chen , A. J. Roberts , J. E. Bunder

This is the first part of our study of inertial manifolds for the system of 1D reaction-diffusion-advection equations which is devoted to the case of Dirichlet or Neumann boundary conditions. Although this problem does not initially possess…

Analysis of PDEs · Mathematics 2017-03-02 Anna Kostianko , Sergey Zelik

A version of fractional diffusion on bounded domains, subject to 'homogeneous Dirichlet boundary conditions' is derived from a kinetic transport model with homogeneous inflow boundary conditions. For nonconvex domains, the result differs…

Analysis of PDEs · Mathematics 2016-07-05 Pedro Aceves-Sanchez , Christian Schmeiser

In this note, we discuss a poorly known alternative boundary condition to the usual Neumann or `stress-free' boundary condition typically used to weaken boundary layers when diffusion is present but very small. These `diffusion-free'…

Fluid Dynamics · Physics 2024-06-19 Yufeng Lin , Rich Kerswell

We investigate the fractional diffusion approximation of a kinetic equation in the upper-half plane with diffusive reflection conditions at the boundary. In an appropriate singular limit corresponding to small Knudsen number and long time…

Analysis of PDEs · Mathematics 2019-09-04 Ludovic Cesbron , Antoine Mellet , Marjolaine Puel

Although the spatially continuous version of the reaction-diffusion equation has been well studied, in some instances a spatially-discretized representation provides a more realistic approximation of biological processes. Indeed,…

Dynamical Systems · Mathematics 2023-11-27 Jacqueline M. Wentz , David M. Bortz

This paper studies, in dimensions greater than two, stationary diffusion processes in random environment which are small, isotropic perturbations of Brownian motion satisfying a finite range dependence. Such processes were first considered…

Analysis of PDEs · Mathematics 2016-01-26 Benjamin J. Fehrman

In this work, we investigate a reaction-diffusion system in which both species are influenced by self-diffusion. Due to Hopf's boundary lemma, we obtain the boundedness of the classical solution of the system. By considering a particular…

Analysis of PDEs · Mathematics 2024-04-22 Ningning Zhu , Dongpo Hu , Huili Bi

We study existence and uniqueness of solutions to a class of nonlinear degenerate parabolic equations, in bounded domains. We show that there exists a unique solution which satisfies possibly inhomogeneous Dirichlet boundary conditions. To…

Analysis of PDEs · Mathematics 2014-12-08 Fabio Punzo , Marta Strani

Considering the example of interacting Brownian particles we present a linear response derivation of the boundary condition for the corresponding hydrodynamic description (the diffusion equation). This requires us to identify a non-analytic…

Statistical Mechanics · Physics 2009-11-07 M. Fuchs , K. Kroy

The 3D incompressible Euler equations in a bounded domain are most often supplemented with impermeable boundary conditions, which constrain the fluid to neither enter nor leave the domain. We establish well-posedness with inflow, outflow of…

Analysis of PDEs · Mathematics 2024-12-19 Gung-Min Gie , James P. Kelliher , Anna L. Mazzucato

In this article, we study the impact of a change in the type of boundary conditions of an elliptic boundary value problem. In the context of the conductivity equation we consider a reference problem with mixed homogeneous Dirichlet and…

Analysis of PDEs · Mathematics 2021-06-15 Eric Bonnetier , Charles Dapogny , Michael S. Vogelius

Due to computational complexity, fluid flow problems are mostly defined on a bounded domain. Hence, capturing fluid outflow calls for imposing an appropriate condition on the boundary where the said outflow is prescribed. Usually, the…

Analysis of PDEs · Mathematics 2021-09-22 John Sebastian H. Simon , Hirofumi Notsu

The justification of hydrodynamic limits in non-convex domains has long been an open problem due to the singularity at the grazing set. In this paper, we investigate the unsteady neutron transport equation in a general bounded domain with…

Analysis of PDEs · Mathematics 2023-03-28 Zhimeng Ouyang

The drift diffusion model (DDM) is a model of sequential sampling with diffusion (Brownian) signals, where the decision maker accumulates evidence until the process hits a stopping boundary, and then stops and chooses the alternative that…

Econometrics · Economics 2022-10-12 Drew Fudenberg , Whitney K. Newey , Philipp Strack , Tomasz Strzalecki

The classical approach to diffusion processes is based on Fick's law that the flux is proportional to the concentration gradient. Various phenomena occurring during propagation of penetrating liquids in polymers show that this type of…

Analysis of PDEs · Mathematics 2010-12-10 Dmitry A. Vorotnikov

We consider a class of reaction-diffusion equations with a stochastic perturbation on the boundary. We show that in the limit of fast diffusion, one can rigorously approximate solutions of the system of PDEs with stochastic Neumann boundary…

Analysis of PDEs · Mathematics 2014-08-13 Wael W. Mohammed , Dirk Blömker

We consider a waveguide modeled by the Laplacian in a straight planar strip. The Dirichlet boundary condition is taken on the upper boundary, while on the lower boundary we impose periodically alternating Dirichlet and Neumann condition…

Spectral Theory · Mathematics 2015-05-20 Denis Borisov , Renata Bunoiu , Giuseppe Cardone

In this work, we introduce a new difference equation which is discrete analogue of Diffusion differential equation and analyze some essential spectral properties, Diffusion difference operator is self-adjoint, eigenvalues of this problem…

Spectral Theory · Mathematics 2017-05-03 Erdal Bas , Ramazan Ozarslan

In this paper, we propose nonlocal diffusion models with Dirichlet boundary. These nonlocal diffusion models preserve the maximum principle and also have corresponding variational form. With these good properties, we can prove the…

Analysis of PDEs · Mathematics 2024-08-13 Yanzun Meng , Zuoqiang Shi