Concentration of cones in the Alt-Phillips problem
Ovidiu Savin, Hui Yu
TL;DR
The paper analyzes minimizers of the Alt-Phillips energy $\mathcal{E}_\gamma$ for γ near 1 and proves that minimizing cones concentrate around obstacle-problem cones. It exploits a transformed solution to obtain 2-homogeneity, proves a key integral inequality for parabola solutions, and shows stability to deduce that limits are exactly the symmetric cones $P_k$ (radial in a $k$-dimensional subspace and invariant perpendicular to it). As γ→1, minimizers converge, up to rotation, to one of the cones in $\{P_k\}_{k=0}^d$, providing a first instance of concentration-induced symmetry in a free boundary problem. The results sharpen the understanding of singular cone limits and highlight a structured, symmetric limiting behavior governed by the obstacle problem.
Abstract
We study minimizing cones in the Alt-Phillips problem when the exponent γ is close to 1. When γ converges to 1, we show that the cones concentrate around symmetric solutions to the classical obstacle problem. To be precise, the limiting profiles are radial in a subspace and invariant in directions perpendicular to that subspace.
