English

Lagrangian submanifolds of the complex hyperbolic quadric

Differential Geometry 2020-02-25 v1

Abstract

We consider the complex hyperbolic quadric Qn{Q^*}^n as a complex hypersurface of complex anti-de Sitter space. Shape operators of this submanifold give rise to a family of local almost product structures on Qn{Q^*}^n, which are then used to define local angle functions on any Lagrangian submanifold of Qn{Q^*}^n. We prove that a Lagrangian immersion into Qn{Q^*}^n can be seen as the Gauss map of a spacelike hypersurface of (real) anti-de Sitter space and relate the angle functions to the principal curvatures of this hypersurface. We also give a formula relating the mean curvature of the Lagrangian immersion to these principal curvatures. The theorems are illustrated with several examples of spacelike hypersurfaces of anti-de Sitter space and their Gauss maps. Finally, we classify some families of minimal Lagrangian submanifolds of Qn{Q^*}^n: those with parallel second fundamental form and those for which the induced sectional curvature is constant. In both cases, the Lagrangian submanifold is forced to be totally geodesic.

Keywords

Cite

@article{arxiv.2002.10314,
  title  = {Lagrangian submanifolds of the complex hyperbolic quadric},
  author = {Joeri Van der Veken and Anne Wijffels},
  journal= {arXiv preprint arXiv:2002.10314},
  year   = {2020}
}