We survey some new and old uniqueness results for Hessian equations such as special Lagrangian equations, Monge-Ampere equations, and symmetric Hessian equations. In particular, a unified approach to quadratic asymptote of solutions over exterior domains--based on an "exterior" Evans-Krylov, corresponding to Allard-Almgren's uniqueness of tangent cones in minimal surface situation--will be presented (joint with D.S. Li and Zh.S. Li). Special Lagrangian and Monge-Ampere equations are the potential equations for minimal and maximal "gradient" graphs in Euclid and pseudo-Euclid spaces respectively.

Note: This is a joint seminar with differential geometry.