On global solutions to semilinear elliptic equations related to the one-phase free boundary problem

Motivated by its relation to models of flame propagation, we study globally Lipschitz solutions of $\Delta u=f(u)$ in $\mathbb{R}^n$, where $f$ is smooth, nonnegative, with support in the interval $[0,1]$. In such setting, any 'blow-down' of the solution $u$ will converge to a global solut...

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Detalles Bibliográficos
Autores: Fernandez-Real, Xavier, Ros, Xavier
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2019
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/194026
Acceso en línea:https://hdl.handle.net/2445/194026
Access Level:acceso abierto
Palabra clave:Laplacià
Equacions diferencials el·líptiques
Equacions en derivades parcials
Distribució (Teoria de la probabilitat)
Laplacian operator
Elliptic differential equations
Partial differential equations
Distribution (Probability theory)
Descripción
Sumario:Motivated by its relation to models of flame propagation, we study globally Lipschitz solutions of $\Delta u=f(u)$ in $\mathbb{R}^n$, where $f$ is smooth, nonnegative, with support in the interval $[0,1]$. In such setting, any 'blow-down' of the solution $u$ will converge to a global solution to the classical onephase free boundary problem of Alt-Caffarelli. In analogy to a famous theorem of Savin for the Allen-Cahn equation, we study here the $1 \mathrm{D}$ symmetry of solutions $u$ that are energy minimizers. Our main result establishes that, in dimensions $n<6$, if $u$ is axially symmetric and stable then it is $1 \mathrm{D}$.