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, non-negative, 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 one-phase free boundary problem of Alt–Caffarelli.
In analogy to a famous theorem of Savin for the Allen–Cahn equation, we study here the 1D 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 1D.
Citation: |
[1] |
H. W. Alt and L. Caffarelli, Existence and regularity for a minimum problem with free boundary, J. Reine Angew. Math., 325 (1981), 105-144.
![]() ![]() |
[2] |
L. Ambrosio and X. Cabré, Entire solutions of semilinear elliptic equations in $ \mathbb{R}^3$ and a conjecture of De Giorgi, J. Amer. Math. Soc., 13 (2000), 725-739.
doi: 10.1090/S0894-0347-00-00345-3.![]() ![]() ![]() |
[3] |
J. D. Buckmaster and G. S. Ludford, Theory of Laminar Flames, Cambridge Univ. Press, Cambridge, 1982.
![]() ![]() |
[4] |
X. Cabré, Regularity of minimizers of semilinear elliptic problems up to dimension four, Comm. Pure Applied Mathematics, 63 (2010), 1362-1380.
doi: 10.1002/cpa.20327.![]() ![]() ![]() |
[5] |
X. Cabré and A. Capella, On the stability of radial solutions of semilinear elliptic equations in all of $ \mathbb{R}^n$, C. R. Acad. Sci. Paris, Ser. I, 338 (2004), 769-774.
doi: 10.1016/j.crma.2004.03.013.![]() ![]() ![]() |
[6] |
X. Cabré and X. Ros-Oton, Regularity of stable solutions up to dimension 7 in domains of double revolution, Comm. Partial Differential Equations, 38 (2013), 135-154.
doi: 10.1080/03605302.2012.697505.![]() ![]() ![]() |
[7] |
X. Cabré and J. Terra, Saddle-shaped solutions of bistable diffusion equations in all of $ \mathbb{R}^{2m}$, J. Eur. Math. Soc., 11 (2009), 819-843.
doi: 10.4171/JEMS/168.![]() ![]() ![]() |
[8] |
L. Caffarelli, D. Jerison and C. Kenig, Global energy minimizers for free boundary problems and full regularity in three dimension, Contemp. Math., 350 (2004), 83-97.
doi: 10.1090/conm/350/06339.![]() ![]() ![]() |
[9] |
L. Caffarelli and S. Salsa, A Geometric Approach To Free Boundary Problems, AMS, 2005.
doi: 10.1090/gsm/068.![]() ![]() ![]() |
[10] |
L. Caffarelli and J. L. Vázquez, A free-boundary problem for the heat equation arising in flame propagation, Trans. Amer. Math. Soc., 347 (1995), 411-441.
doi: 10.1090/S0002-9947-1995-1260199-7.![]() ![]() ![]() |
[11] |
E. De Giorgi, Proceedings of the International Meeting on Recent Methods in Nonlinear Analysis (Rome, 1978), (Pitagora, Bologna, Italy), 131–188.
![]() |
[12] |
D. De Silva and D. Jerison, A singular energy minimizing free boundary, J. Reine Angew. Math., 635 (2009), 1-22.
doi: 10.1515/CRELLE.2009.074.![]() ![]() ![]() |
[13] |
L. Dupaigne and A. Farina, Stable solutions of $ -\Delta u = f(u) $ in $ \mathbb{R}^N $, J. Eur. Math. Soc., 12 (2010), 855-882.
doi: 10.4171/JEMS/217.![]() ![]() ![]() |
[14] |
A. Farina, Propriétés qualitatives de solutions d'équations et systèmes d'équations non-linéaires, Habilitation à diriger des recherches, Paris Ⅵ, 2002.
![]() |
[15] |
A. Farina and E. Valdinoci, The State of the Art for a Conjecture of De Giorgi and Related Problems, Recent Progress on Reaction-Diffusion Systems and Viscosity Solutions, World Scientific, 2008.
doi: 10.1142/9789812834744_0004.![]() ![]() ![]() |
[16] |
D. Jerison and O. Savin, Some remarks on stability of cones for the one-phase free boundary problem, Geom. Funct. Anal., 25 (2015), 1240-1257.
doi: 10.1007/s00039-015-0335-6.![]() ![]() ![]() |
[17] |
Y. Liu, K. Wang and J. Wei, Global minimizers of the Allen–Cahn equation in dimension $ n = 8$, J. Math. Pures Appl., 108 (2017), 818-840.
doi: 10.1016/j.matpur.2017.05.006.![]() ![]() ![]() |
[18] |
Y. Liu, K. Wang and J. Wei, On one phase free boundary problem in $ \mathbb{R}^n$, preprint, arXiv: 1705.07345, (2017).
![]() |
[19] |
A. Petrosyan and N. K. Yip, Nonuniqueness in a free boundary problem from combustion, J. Geom. Anal., 18 (2007), 1098-1126.
doi: 10.1007/s12220-008-9044-9.![]() ![]() ![]() |
[20] |
O. Savin, Regularity of flat level sets in phase transitions, Ann. of Math., 169 (2009), 41-78.
doi: 10.4007/annals.2009.169.41.![]() ![]() ![]() |
[21] |
P. Sternberg and K. Zumbrun, Connectivity of phase boundaries in strictly convex domains, Arch. Rational Mech. Anal., 141 (1998), 375-400.
doi: 10.1007/s002050050081.![]() ![]() ![]() |
[22] |
G. S. Weiss, A singular limit arising in combustion theory: Fine properties of the free boundary, Calc. Var. PDE, 17 (2003), 311-340.
![]() ![]() |
Representation of
Representation of the cases (ⅰ)