We use Warren–Yuan’s (Warren and Yuan 2009) superisoperimetric inequality
on the level sets of subharmonic functions, which is available only in
two dimensions, to derive a modified Hessian bound for solutions of the
two-dimensional Lagrangian mean curvature equation. We assume the Lagrangian
phase to be supercritical with bounded second derivatives. Unlike in
(Bhattacharya 2021), the simplified approach in this paper does not require the
Michael–Simon mean value and Sobolev inequalities on generalized submanifolds of
(Michael and Simon 1973).
Keywords
Lagrangian mean curvature, critical phase, supercritical
phase, Hessian estimates