Fully non-linear elliptic equations on complex manifolds
Rirong Yuan
TL;DR
This work studies fully nonlinear elliptic equations of Hessian type on Hermitian manifolds, formulating $F(\chi+\sqrt{-1}\partial\overline{\partial}u)=\psi$ with $F=f(\lambda[\omega^{-1}(\chi+\sqrt{-1}\partial\overline{\partial}u)])$ on a Gårding-type cone $\Gamma$ and under ellipticity, concavity, nondegeneracy, plus the $\mathcal{C}$-subsolution condition. The authors prove global $C^{2,\alpha}$-estimates for closed manifolds via a refined blow-up argument and Evans–Krylov theory, and develop a quantitative boundary framework enabling sharp $C^{2}$-type boundary estimates to solve the Dirichlet problem, including degenerate right-hand sides, on manifolds with boundary and on product spaces. They introduce a set of technical tools—a refined subsolution lemma, a monotonicity result, blow-up and Liouville-type analysis, and a new quantitative eigenvalue lemma (Yuan’s lemma)—to control interior and boundary behavior under optimal cone conditions. The results extend solvability and regularity for general Hessian-type equations to curved, non-Kähler Hermitian manifolds, provide construction of subsolutions on products, and offer a robust framework for degenerate and boundary-influenced problems with potential geometric applications.
Abstract
In this paper, we study a broad class of fully nonlinear elliptic equations on Hermitian manifolds. On one hand, under the optimal structural assumptions we derive $C^{2,α}$-estimate for solutions of the equations on closed Hermitian manifolds. On the other hand, we treat the Dirichlet problem. In both cases, we prove the existence theorems with unbounded condition.
