Special Session 43: 

A spiral interface and quantitative stability for the Alt-Caffarelli-Friedman monotonicity formula

Mark Allen
Brigham Young University
USA
Co-Author(s):    Dennis Kriventsov; Robin Neumayer
Abstract:
We give an example of a pair of nonnegative subharmonic functions with disjoint support for which the Alt-Caffarelli-Friedman (ACF) monotonicity formula has strictly positive limit at the origin, and yet the interface between the supports lacks a tangent at the origin. I will also discuss a quantitative stability result for the ACF monotonicity formula. This is joint work with Dennis Kriventsov and Robin Neumayer.