Parameter Height bounds for the Zilber Pink conjecture for PEL types III and IV
Bijay Raj Bhatta
TL;DR
This work establishes a conditional Zilber–Pink statement for the intersection of an irreducible Hodge-generic subvariety of $\\mathcal{A}_g$ with simple PEL-type III/IV special subvarieties, assuming the Large Galois Orbits conjecture. It introduces a parameter-height bound for the arithmetic inputs of the Pila–Zannier strategy in Albert types III and IV, and develops a unitary-basis framework to control discriminants and covolumes. Extending prior types I/II results, the paper obtains finiteness and non-density conclusions for curves and more general subvarieties, linking Shimura data, o-minimality, and height bounds. The methods combine a refined classification of conjugacy classes, a definable-sets counting approach, and inductive height-control techniques that may inform unconditional progress via LGO in broader PEL contexts.
Abstract
We prove the Zilber-Pink conjecture to the intersection of an irreducible Hodge generic algebraic subvariety $ V \subset \mathcal{A}_g$ with special subvarieties of all simple PEL types other than $\mathbb{Z}$, under the assumption of the Large Galois Orbits conjecture. In particular, we establish parameter height bounds for the arithmetic ingredients of the Pila-Zannier strategy in the case of Albert types III and IV. This paper is a sequel to Daw and Orr's paper "Lattices with skew-Hermitian forms over division algebras and unlikely intersections" 2023.
