“…All of these results exploit some underlying structure of the given background to obtain a priori L ∞ estimates for the metric tensor along the flow. In the setting of Kähler-Ricci flow, reduced to a parabolic Monge-Ampere equation, this corresponds to having a C 1,1 estimate for the potential, at which point one applies either the Evans-Krylov method [5,7] to obtain a C 2,α estimate, or Calabi's C 3 estimate [2,18,13], after which Schauder estimates can be applied to obtain C ∞ estimates. As pluriclosed metrics cannot be described locally by a single function, the pluriclosed flow does not admit a scalar reduction, so the method of Evans-Krylov cannot be applied.…”