A universal Hölder estimate up to dimension 4 for stable solutions to half-Laplacian semilinear equations

We study stable solutions to the equation , posed in a bounded domain of . For nonnegative convex nonlinearities, we prove that stable solutions are smooth in dimensions . This result, which was known only for , follows from a new interior Hölder estimate that is completely independent of the nonlin...

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Detalles Bibliográficos
Autores: Cabré Vilagut, Xavier|||0000-0001-5682-3135, Sanz Perela, Tomás|||0000-0002-1210-1111
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/388320
Acceso en línea:https://hdl.handle.net/2117/388320
https://dx.doi.org/10.1016/j.jde.2022.02.001
Access Level:acceso abierto
Palabra clave:Differential equations, Partial
Half-Laplacian
Stable solutions
Extremal solution
Interior estimates
Dirichlet problem
Equacions en derivades parcials
Classificació AMS::35 Partial differential equations::35B Qualitative properties of solutions
Àrees temàtiques de la UPC::Matemàtiques i estadística::Equacions diferencials i integrals::Equacions en derivades parcials
Descripción
Sumario:We study stable solutions to the equation , posed in a bounded domain of . For nonnegative convex nonlinearities, we prove that stable solutions are smooth in dimensions . This result, which was known only for , follows from a new interior Hölder estimate that is completely independent of the nonlinearity f. A main ingredient in our proof is a new geometric form of the stability condition. It is still unknown for other fractions of the Laplacian and, surprisingly, it requires convexity of the nonlinearity. From it, we deduce higher order Sobolev estimates that allow us to extend the techniques developed by Cabré, Figalli, Ros-Oton, and Serra for the Laplacian. In this way we obtain, besides the Hölder bound for , a universal estimate in all dimensions. Our bound is expected to hold for , but this has been settled only in the radial case or when . For other fractions of the Laplacian, the expected optimal dimension for boundedness of stable solutions has been reached only when , even in the radial case.