2016/07/13 by Georgiev, Bogdan
#Analysis of PDEs (math.AP) #Differential Geometry (math.DG) #FOS: Mathematics #Spectral Theory (math.SP)
paper · doi:10.48550/arxiv.1607.03816
We discuss the asymptotic lower bound on the inner radius of nodal domains that arise from Laplacian eigenfunctions ϕλ on a closed Riemannian manifold (M,g) . First, in the real-analytic case we present an improvement of the currently best known bounds, due to Mangoubi (\citeMan1). Furthermore, using recent results of Hezari (\citeHezari, \citeHezari2) we obtain log -type improvements in the case of negative curvature and improved bounds for (M,g) possessing an ergodic geodesic flow. Second, we discuss the relation between the distribution of the L2 norm of an eigenfunction ϕλ and the inner radius of the corresponding nodal domains. In the spirit of the works of Colding-Minicozzi and Jakobson-Mangoubi, we consider a covering of good cubes and show that, if a nodal domain is sufficiently well covered by good cubes, then its inner radius is large.