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JOURNALS // Contemporary Mathematics. Fundamental Directions // Archive

CMFD, 2022 Volume 68, Issue 4, Pages 564–574 (Mi cmfd474)

Boundary singular problems for quasilinear equations involving mixed reaction-diffusion

L. Véron

Institut Denis Poisson, Université de Tours, Tours, France

Abstract: We study the existence of solutions to the problem
\begin{equation} \begin{array}{rl} -\Delta u+u^p-M|\nabla u|^q=0 & \text{in } \Omega,\\ u=\mu & \text{on } \partial\Omega \end{array} \end{equation}
in a bounded domain $\Omega$, where $p>1$, $1<q<2$, $M>0$, $\mu$ is a nonnegative Radon measure in $\partial\Omega$, and the associated problem with a boundary isolated singularity at $a\in\partial\Omega,$
\begin{equation} \begin{array}{rl} -\Delta u+u^p-M|\nabla u|^q=0 & \text{in } \Omega,\\ u=0 & \text{on } \partial\Omega\setminus\{a\}. \end{array} \end{equation}
The difficulty lies in the opposition between the two nonlinear terms which are not on the same nature. Existence of solutions to (1) is obtained under a capacitary condition
$$ \mu(K)\leq c\min\left\{cap^{\partial\Omega}_{\frac{2}{p},p'},cap^{\partial\Omega}_{\frac{2-q}{q},q'}\right\} \text{for all compacts }K\subset\partial\Omega. $$
Problem (2) depends on several critical exponents on $p$ and $q$ as well as the position of $q$ with respect to $\dfrac{2p}{p+1}$.

Keywords: reaction-diffusion equation, boundary singular problem, measure as boundary data, isolated boundary singularity.

UDC: 517.957

DOI: 10.22363/2413-3639-2022-68-4-564-574



© Steklov Math. Inst. of RAS, 2026