Exterior Dirichlet Problems for Hessian Quotient Equations of Mixed Type

Abstract

We study the exterior Dirichlet problem for the mixed Hessian quotient equation \[ \frac{\sigma_k(\eta(D^2 u))}{\sigma_l(\eta(D^2 u))} = 1, \] where $\eta(M) = (\operatorname{tr} M)I - M$. We establish existence and uniqueness of smooth admissible solutions with prescribed quadratic asymptotics at infinity, and obtain full derivative decay of the remainder. The proof relies on a three-stage subsolution construction.