The Monge-Amp\`ere Equation with Guillemin Boundary Conditions

Existence and boundary regularity away from the corners are established for two-dimensional Monge-Amp`{e}re equations on convex polytopes with Guillemin boundary conditions. An important step is to derive an expansion in terms of functions $y^n$ and $y^n\log y$ for solutions to equations of the form $\det D^2u(x,y) = y^{-1}$ in a half-ball.