Geometry and arithmetic of non-rigid families of Calabi-Yau 3-folds; questions and examples

Abstract

In this note we speculate about the structure of maximal product subvarieties in moduli stacks of Calabi-Yau manifolds. We discuss examples for quintic hypersurfaces in the four dimensional projective space.

Final version: AMSLaTeX (with gen-p-l.cls), 10 pages. Several typos corrected. Proofs in Section 4 reformulated. One reference added