Stable solutions to the fractional Allen-Cahn equation in the nonlocal perimeter regime

We study stable solutions to the fractional Allen-Cahn equation (-¿)^(s/2)u = u - u^3, |u|<1 in R^3. For every s ¿ (0,1) and dimension n >=2, we establish sharp energy estimates, density estimates, and the convergence of blow-downs to stable nonlocal s-minimal cones. As a consequence, we obtai...

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Bibliographic Details
Authors: Cabré Vilagut, Xavier|||0000-0001-5682-3135, Cinti, Eleonora, Serra Montolí, Joaquim
Format: article
Publication Date:2025
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2117/446469
Online Access:https://hdl.handle.net/2117/446469
https://dx.doi.org/10.1353/ajm.2025.a966290
Access Level:Open access
Keyword:Differential equations, Partial
Equacions en derivades parcials
Classificació AMS::35 Partial differential equations::35R Miscellaneous topics involving partial differential equations
Àrees temàtiques de la UPC::Matemàtiques i estadística::Equacions diferencials i integrals::Equacions en derivades parcials
Description
Summary:We study stable solutions to the fractional Allen-Cahn equation (-¿)^(s/2)u = u - u^3, |u|<1 in R^3. For every s ¿ (0,1) and dimension n >=2, we establish sharp energy estimates, density estimates, and the convergence of blow-downs to stable nonlocal s-minimal cones. As a consequence, we obtain a new classification result: if for some pair (n,s), with n>=3, hyperplanes are the only stable nonlocal s-minimal cones in R^n/{0}, then every stable solution to the fractional Allen-Cahn equation in R^n is 1D, namely, its level sets are parallel hyperplanes. Combining this result with the classification of stable s-minimal cones in R^3\{0} for s = 1 obtained by the authors in a recent paper, we give positive answers to the ``stability conjecture'' in R^3 and to the ``De Giorgi conjecture'' in R^4 for the fractional Allen-Cahn equation when the order s ¿ (0,1) of the operator is sufficiently close to 1.