Uniqueness of nodal radial solutions superlinear elliptic equations in a ball

Abstract

The Dirichlet problem

is considered, where B = {x ∈ ℝ^N : |x| < 1}, N ≥ 3, p > 1, K ∈ C²[0, 1] and K(r) > 0 for 0 ≤ r ≤ 1. A sufficient condition is derived for the uniqueness of radial solutions of (*) possessing exactly k − 1 nodes, where k ∈ ℕ. It is also shown that there exists K ∈ C^∞[0, 1] such that (*) has at least three radial solutions possessing exactly k − 1 nodes, in the case 1 < p < (N + 2)/(N − 2).