Sublinear elliptic problems under radiality. Harmonic groups and Euclidean spaces
arXiv:1711.01931
Abstract
Let be the Laplace operator on , or the Laplace Beltrami operator on the harmonic group (in particular on a rank one noncompact symmetric space). For the equation we give necessary and sufficient conditions for the existence of entire bounded or large solutions under the hypothesis of radiality of with respect to the first variable. A Harnack-type inequality for positive continuous solutions is also proved.