Solvability of Hessian quotient equations in exterior domains

In this paper, we study the Dirichlet problem of Hessian quotient equations of the form $S_k(D<^>2u)/S_l(D<^>2u)=g(x)$ in exterior domains. For $g\equiv \mbox {const.}$, we obtain the necessary and sufficient conditions on the existence of radially symmetric solutions. For g being a perturbation of a generalized symmetric function at infinity, we obtain the existence of viscosity solutions by Perron's method. The key technique we develop is the construction of sub- and supersolutions to deal with the non-constant right-hand side g.