Ngaiming Mok, HKU, Hong Kong

Holomorphic isometries of the complex unit ball into bounded symmetric domains

 

Abstract

In earlier works we proved that any germ of holomorphic isometry f: DD' (up to normalizing constants) with respect to the Bergman metric between two bounded domains extends to a proper holomorphic isometry whenever the Bergman metrics are complete, and that moreover the graph of the map extends to an affine-algebraic variety provided that the Bergman kernels are rational functions. In particular this applies to bounded symmetric domains in their Harish-Chandra realizations.  We have also constructed examples of nonstandard holomorphic isometries of the Poincaré disk into certain bounded symmetric domains. It has been unknown for some time whether the complex unit ball Bn, n ≥ 2, can be holomorphically and isometrically embedded in a nonstandard way into some bounded symmetricdomains.

 

      We give a construction of such isometric embeddings for n ≥ 2, and show some examples where one can prove uniqueness up to automorphisms of the domain and target spaces.  We also explain the relevance of holomorphic isometric embeddings of the complex unit ball for the Hyperbolic Ax-Lindemann Conjecture for arbitrary lattices in functional transcendence theory.