1999 Local structure of solutions of the Dirichlet problem for $N$-dimensional reaction-diffusion equations in bounded domains
Ugur G. Abdulla
Adv. Differential Equations 4(2): 197-224 (1999). DOI: 10.57262/ade/1366291413

Abstract

We consider the problem \begin{alignat}{2} u_t-\Delta u^m+bu^\beta & =0, &\quad& (x,t)\ \epsilon\ Q_T =\Omega\times(0,T]\\ u(x,t) & =0, &\quad& (x,t)\ \epsilon\ S_T=\partial\Omega\times(0,T]\\ u(x,0) & =u_0(x), &\quad& x\ \epsilon\ \Omega, \end{alignat} where $m\geq 1,$ $ b \in R^1,$ $ \beta>0, $ $ T>0;$ $ \Omega$ is a bounded, connected domain in $R^N$ with compact boundary, which is assumed to be piecewise smooth and to satisfy the exterior sphere condition. Let $u_0 \in C(\bar\Omega),$ $ u_0>0$ for $x \in \Omega$ and $u_0=0$ for $x\in \partial\Omega$. Assume also that $u_0$ is smooth near $\partial\Omega$. We show that the small time behaviour of the solution near the boundary $\partial\Omega$ depends on the relative strength of the diffusion and reaction terms near the boundary, that is to say on the function $$ \gamma(\bar x)=\lim\limits_{x\to\bar x} \bigl(\Delta u_0^m\big/bu^\beta_0\bigr),\quad\bar x \in \partial\Omega,\quad x\in \Omega. $$ We are essentially interested in the initial development of the interface between the dead core and the positive $u(x,t)$ field. In all possible cases, the small time behaviour of the interface is found, together with the local solution.

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Ugur G. Abdulla. "Local structure of solutions of the Dirichlet problem for $N$-dimensional reaction-diffusion equations in bounded domains." Adv. Differential Equations 4 (2) 197 - 224, 1999. https://doi.org/10.57262/ade/1366291413

Information

Published: 1999
First available in Project Euclid: 18 April 2013

zbMATH: 0994.35070
MathSciNet: MR1674351
Digital Object Identifier: 10.57262/ade/1366291413

Subjects:
Primary: 35K57

Rights: Copyright © 1999 Khayyam Publishing, Inc.

Vol.4 • No. 2 • 1999
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