Abstract In this paper, we proved that for a bounded Hopf-symmetric domain Ω in a non-compact rank one symmetric space M, the second Dirichlet eigenvalue ₂ () ₂ (B₁) λ 2 (Ω) ≤ λ 2 (B 1) where B₁ B 1 is a geodesic ball in M such that ₁ () = ₁ (B₁) λ 1 (Ω) = λ 1 (B 1). This generalizes the work of Ashbaugh & Benguria, Benguria & Linde for bounded domains in constant curvature spaces.
Yusen Xia (Fri,) studied this question.