Uniqueness of the blow-up for some Alt-Phillips cones

Abstract: We establish uniqueness of blow-ups, with sharp quantitative convergence, for several classes of singular minimizing cones in the Alt-Phillips problem, in the range $γ\in(0,2)$. As a consequence, we obtain uniqueness at every free boundary point for $γ\in(1,2)$ in dimensions $d=2,3,4$, and for $γ\in\left(1,\frac32\right)$ in dimensions $d\geq 5$. The proof is based on three new logarithmic epiperimetric inequalities. The sharp distinction between polynomial and logarithmic convergence is governed by a finite-dimensional integrability condition (sub-integrability) for the spherical linearized problem. We prove this sharpness for radial and cylindrical cones through an explicit integrability and bifurcation analysis, and show that logarithmic convergence may be sharp even in dimension two. In contrast, we show that the one-dimensional cone is exceptional: although the integrability condition fails, the convergence is polynomial. Finally, we characterize the minimality of the radial cone in terms of $γ$ and $d$ by means of a one-dimensional calibration argument, exhibiting in dimension $d\geq6$ a nontrivial regime in which the radial cone is stable but not minimizing.