Liouville type results for semilinear elliptic equation and inequality on pseudo-Hermitian manifolds
Biqiang Zhao
TL;DR
The paper develops Liouville-type theorems for semilinear equations and differential inequalities on pseudo-Hermitian manifolds, extending classical results to CR and sub-Riemannian settings. By leveraging a generalized Jerison–Lee differential identity and subcritical nonlinearities, the authors establish rigidity results for equations of the form $Δ_b u + 2n^2 F(u)=0$ under Sasakian curvature and volume-growth hypotheses, and prove nonexistence (or constancy) results for the inequality $Δ_b u + F(u) ≤ 0$ under corresponding volume bounds. The work combines precise energy estimates, cut-off arguments, and curvature-volume conditions to show that positive solutions must be constant (i.e., $F(u)=0$) in large classes of pseudo-Hermitian manifolds, including Sasakian manifolds. These results extend CR Yamabe-type Liouville theory to sub-Riemannian geometry and provide tools for semilinear PDEs in this geometric context.
Abstract
In this paper, we study the semilinear elliptic equation and inequality on pseudo-Hermitian manifolds. In particular, we first obtain a Liouville theorem for the equation $Δ_b u+F(u)=0$ based on a generalized Jerison-Lee's formula. Next, we prove the nonexistence of a positive solution to the inequality $Δ_b u+F(u)\leq 0$ under the volume estimate.
