2025/06/12 by Santiago Castañeda Montoya, Montoya, Santiago Castañeda, Carlos Olmos +1
Mathematics · #Geometric and Algebraic Topology #Geometric Analysis and Curvature Flows #Mathematical Dynamics and Fractals
paper · pdf · doi:10.48550/arxiv.2506.11323
We prove that the restricted normal holonomy group of a Kähler submanifold of the complex hyperbolic space ℂHn is always transitive, provided the index of relative nullity is zero. This contrasts with the case of ℂPn, where a Berger type result was proved by Console, Di Scala, and the second author. The proof is based on lifting the submanifold to the pseudo-Riemannian space ℂn,1 and developing new tools to handle the difficulties arising from possible degeneracies in holonomy tubes and associated distributions. In particular, we introduce the notion of weakly polar actions and a framework for dealing with degenerate submanifolds. These techniques could contribute to a broader understanding of submanifold geometry in spaces with indefinite signature, offering new insight into submanifolds in the dual setting of complex projective geometry.