On the nodal set conjecture for the $p$-Laplacian in circularly symmetric domains
Vladimir Bobkov
TL;DR
The paper addresses Payne's nodal set conjecture for the Dirichlet $p$-Laplacian in circularly symmetric domains of arbitrary dimension. It employs the moving polarization (a two-point rearrangement) method, along with a precise circular-symmetry framework, to control the location of the nodal set of second eigenfunctions. Under assumptions $(O_1)$--$(O_4)$, it proves that $\mathrm{dist}(\mathcal{Z}(u),\partial\Omega)=0$, extending known planar results to nonlinear settings and higher dimensions. The work provides a robust nonlinear/nodal-set framework via polarization that could extend to other symmetries and domain regularities, highlighting the versatility of two-point rearrangements in eigenvalue problems.
Abstract
In 1990, Pütter shown that the nodal line of any second eigenfunction of the Dirichlet Laplacian on a planar bounded simply connected domain $Ω$ intersects the boundary $\partialΩ$ provided $Ω$ has the circular symmetry. By adopting the method of moving polarization, we establish similar information on the nodal set of second eigenfunctions of the Dirichlet $p$-Laplacian on circularly symmetric domains in arbitrary higher dimension.
