Special Session 146: Nonlinear differential equations: control, delay, and boundary value problems

The degenerate quenching problem
Rafayel Teymurazyan
KAUST
Saudi Arabia
Co-Author(s):    D.J. Ara\`ujo, J.M. Urbano
Abstract:
We study minimizers of non-differentiable functionals modeled on the degenerate quenching problem. Our main result establishes the finiteness of the (n-1)-dimensional Hausdorff measure of the free boundary. The proof is based on optimal gradient decay estimates obtained from an intrinsic Harnack-type inequality, along with a detailed analysis in a flatness regime, where minimizers enjoy improved regularity. Our arguments provide an alternative proof of classical results of Phillips and, although developed in the degenerate setting, also offer insights relevant to the singular case.