Uniqueness and Properties of Distributional Solutions of Nonlocal Equations of Porous Medium Type

We study the uniqueness, existence, and properties of bounded distributional solutions of the initial value problem for the anomalous diffusion equation $\partial_tu-\mathcal{L}^\mu [\varphi (u)]=0$. Here $\mathcal{L}^\mu$ can be any nonlocal symmetric degenerate elliptic operator including the frac...

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Bibliographic Details
Authors: Del Teso, F., Endal, J., Jacobsen, E.R.
Format: article
Status:Versión aceptada para publicación
Publication Date:2016
Country:España
Institution:Basque Center for Applied Mathematics (BCAM)
Repository:BIRD. BCAM's Institutional Repository Data
OAI Identifier:oai:bird.bcamath.org:20.500.11824/307
Online Access:http://hdl.handle.net/20.500.11824/307
Access Level:Open access
Keyword:uniqueness
distributional solutions
nonlinear degenerate diffusion
porous medium equation
Stefan problem
fractional Laplacian
nonlocal operators
existence
stability
local limits
continuous dependence
numerical approximation
convergence
Description
Summary:We study the uniqueness, existence, and properties of bounded distributional solutions of the initial value problem for the anomalous diffusion equation $\partial_tu-\mathcal{L}^\mu [\varphi (u)]=0$. Here $\mathcal{L}^\mu$ can be any nonlocal symmetric degenerate elliptic operator including the fractional Laplacian and numerical discretizations of this operator. The function $\varphi:\mathbb{R} \to \mathbb{R}$ is only assumed to be continuous and nondecreasing. The class of equations include nonlocal (generalized) porous medium equations, fast diffusion equations, and Stefan problems. In addition to very general uniqueness and existence results, we obtain stability, $L^1$-contraction, and a priori estimates. We also study local limits, continuous dependence, and properties and convergence of a numerical approximation of our equations.