Fully nonlinear prescribed curvature problems on closed manifolds with negative curvature
Jiaogen Zhang
TL;DR
This work studies fully nonlinear prescribed curvature problems in the negative curvature regime on closed manifolds via the modified Schouten tensor $A_g^t$ and a broad class of concave elliptic operators. Recasting the problem as a scalar PDE $F(W[u])=\psi e^{2u}$, the authors establish robust a priori estimates ($C^0$, gradient, and $C^2$) under Condition $\mathscr{T}$, then solve by a continuity method to obtain existence and uniqueness of a conformal metric within the given conformal class. A key contribution is showing solvability for all $t<1$ under Condition T, with the result holding for all $O(n)$-invariant Gårding-Dirichlet operators, thereby generalizing classical results such as Gursky–Viaclovsky. The paper further applies the framework to the prescribed $\mathcal{M}_p$-curvature problem, providing a unified treatment that encompasses a broad family of curvature functionals between scalar and Ricci curvatures.
Abstract
In this manuscript, we investigate fully nonlinear prescribed curvature problems for the modified Schouten tensor on closed Riemannian manifolds with negative curvature. We prove that whenever the corresponding concave elliptic operator satisfies a structural Condition $T$, which encompasses all $O(n)$-invariant Gårding-Dirichlet operator, such prescribed curvature problems are always solvable.
