Pluriclosed flow, Born-Infeld geometry, and rigidity results for generalized K\"ahler manifolds

We prove long time existence and convergence results for the pluriclosed flow, which imply geometric and topological classification theorems for generalized K\"ahler structures. Our approach centers on the reduction of pluriclosed flow to a degenerate parabolic equation for a $(1,0)$-form, introduced in \cite{ST2}. We observe a number of differential inequalities satisfied by this system which lead to a priori $L^{\infty}$ estimates for the metric along the flow. Moreover we observe an unexpected connection to "Born-Infeld geometry" which leads to a sharp differential inequality which can be used to derive an Evans-Krylov type estimate for the degenerate parabolic system of equations. To show convergence of the flow we generalize Yau's oscillation estimate to the setting of generalized K\"ahler geometry.