Asymptotic Behavior of Infinity Harmonic Functions Near an Isolated Singularity
1 Department of Mathematics, Columbia University, New York, NY 10027 USA
2 Department of Mathematics, University of Kentucky, Lexington, KY 40513 USA
3 Department of Mathematics, University of Texas at Austin, Austin, TX 78712, USA
Correspondence: Correspondence to be sent to: savin{at}math.columbia.edu
In this paper, we prove that if n
2 and x0 is an isolated singularity of a non-negative infinity harmonic function u, then either x0 is a removable singularity of u or u(x)=u(x0)+c|x–x0|+o(|x–x0|) near x0 for some fixed constant c
0. In particular, if x0 is nonremovable, then u has a local maximum or a local minimum at x0. We also prove a Bernstein-type theorem, which asserts that if u is a uniformly Lipschitz continuous, one-side bounded infinity harmonic function in
then it must be a cone function with center at 0.