Monge–Ampère equation
In mathematics, a (real) Monge–Ampère equation is a nonlinear second-order partial differential equation of special kind. A second-order equation for the unknown function u {\displaystyle u} of two variables x {\displaystyle x} , y {\displaystyle y} is of Monge–Ampère type if it is linear in the determinant of the Hessian matrix of u {\displaystyle u} and in the second-order partial derivatives of u {\displaystyle u} .