5.1.3 Almgren’s regularity in the almost Calabi-Yau setting? [04EG]
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5.1.3 Almgren’s regularity in the almost Calabi-Yau setting?
The main reason to impose the Calabi-Yau condition is so that any special Lagrangian closed integral current is an absolute volume minimizer among all closed integral currents in the same homology class, by the calibration inequality (2). If we believe Thomas-Yau conjecture to be valid more generally for almost Calabi-Yau ambient structures, with
then we are naturally motivated to ask if Almgren’s regularity extends to special Lagrangians in this setting:
Question 11.
Suppose is a compactly supported closed integral current inside an almost Calabi-Yau manifold, which is a special Lagrangian in the sense of (1). Does it imply the support of is smooth away from a Hausdorff codimension two subset?
The following observations, left as easy exercises, are indications that almost Calabi-Yau manifolds behave similarly as Calabi-Yau manifolds.
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By a variant of the calibration inequality (2), special Lagrangians minimize the weighted volume
within its homology class.
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Under the smoothness assumption, the mean curvature of a Lagrangian submanifold with phase function satisfies the formula
where means the normal projection of the gradient, and is the derivative of along . Thus for smooth special Lagrangians in a bounded region, we have the a priori bound .