Curvature restrictions for Levi-flat real hypersurfaces in complex projective planes

TL;DR

This paper investigates curvature constraints on Levi-flat real hypersurfaces in complex projective planes, establishing that their totally real Ricci curvature cannot exceed -4, which impacts their possible existence.

Contribution

It introduces a curvature restriction result for Levi-flat hypersurfaces in complex projective planes, linking curvature bounds to the holonomy of Levi foliations.

Findings

Totally real Ricci curvature cannot be greater than -4

Curvature bounds relate to the infinitesimal holonomy of Levi foliation

Results impact the existence questions of Levi-flat hypersurfaces

Abstract

We study curvature restrictions of Levi-flat real hypersurfaces in complex projective planes, whose existence is in question. We focus on its totally real Ricci curvature, the Ricci curvature of the real hypersurface in the direction of the Reeb vector field, and show that it cannot be greater than -4 along a Levi-flat real hypersurface. We rely on a finiteness theorem for the space of square integrable holomorphic 2-forms on the complement of the Levi-flat real hypersurface, where the curvature plays the role of the size of the infinitesimal holonomy of its Levi foliation.