Critical dimensions for polyharmonic operators: The Pucci-Serrin conjecture for solutions of bounded energy
Frédéric Robert
TL;DR
This work resolves the Pucci-Serrin conjecture on critical dimensions for radial solutions of the polyharmonic equation in a unit ball under a uniform energy bound, in the range $2k<n<4k$. The authors develop a uniform, concentration-based analysis that combines sharp Green's function estimates for an operator with an almost Hardy potential, a multi-bubble blow-up framework, and a Pohozaev-Pucci-Serrin-type identity to derive a contradiction unless the energy is controlled. A key technical advance is the construction and precise asymptotics of Green's functions for $\Delta^k+h-V$ under Hardy-type perturbations, together with a robust regularity theory in the spirit of Agmon-Douglis-Nirenberg. The results yield rigorous control of potential bubbles, provide integral and pointwise bounds on Green's functions, and deliver a versatile framework applicable to higher-order elliptic problems with critical nonlinearities.
Abstract
We prove a Pucci-Serrin conjecture on critical dimensions under a uniform bound on the energy. The method is based on the analysis of the Green's function of polyharmonic operators with "almost" Hardy potential.
