2013/11/27 by Patricio Felmer, Ying Wang, Felmer, Patricio +1 · 1 citation
Computer Science · Mathematics · #Advanced Mathematical Modeling in Engineering #Analysis of PDEs (math.AP) #FOS: Mathematics #Nonlinear Partial Differential Equations #Numerical methods in inverse problems #math.AP
paper · pdf · doi:10.48550/arxiv.1311.6952
27 pages, Communications in Contemporary Mathematics 2013
arxiv created 2013/11/27 · openalex publication_date 2013/11/27 · arxiv updated 2013/11/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The aim of this paper is to study radial symmetry and monotonicity properties for positive solution of elliptic equations involving the fractional Laplacian. We first consider the semi-linear Dirichlet problem (-Δ)α u=f(u)+g, \rmin B1, u=0 \rm in B1c, where (-Δ)α denotes the fractional Laplacian, α∈(0,1), and B1 denotes the open unit ball centered at the origin in \RN with N≥2. The function f:[0,∞)→\R is assumed to be locally Lipschitz continuous and g: B1→\R is radially symmetric and decreasing in |x|. In the second place we consider radial symmetry of positive solutions for the equation (-Δ)α u=f(u), \rmin \RN, with u decaying at infinity and f satisfying some extra hypothesis, but possibly being non-increasing. Our third goal is to consider radial symmetry of positive solutions for system of the form (-Δ)α1 u=f1(v)+g1, & \rmin B1, [2mm] (-Δ)α2 v=f2(u)+g2, & \rmin B1, [2mm] u=v =0, & \rmin B1c, where α1,α2∈(0,1), the functions f1 and f2 are locally Lipschitz continuous and increasing in [0,∞), and the functions g1 and g2 are radially symmetric and decreasing. We prove our results through the method of moving planes, using the recently proved ABP estimates for the fractional Laplacian. We use a truncation technique to overcome the difficulty introduced by the non-local character of the differential operator in the application of the moving planes.