A characteristic p analogue of the André--Pink--Zannier conjecture
Yeuk Hay Joshua Lam, Ananth N. Shankar
TL;DR
The paper develops a characteristic $p$ analogue of the André--Pink--Zannier conjecture for ordinary points on Shimura varieties of Hodge type, proving that for points with big monodromy, any infinite prime-to-$p$ Hecke orbit has Zariski closure equal to a finite union of connected components. It also establishes an algebraic analogue of Hecke equidistribution in this setting and provides a function-field formulation over $F=ar{oldsymbol{F}}_p(t)$, together with an application to isogeny finiteness for Jacobians. The strategy combines global–local analysis of prime-to-$p$ Hecke correspondences, degree bounds for translates, and Tate-linearity obtained via Weyl-special points and Chai rigidity, supported by parabolicity results. The results yield a robust positive-characteristic framework for unlikely intersections in Shimura varieties and open avenues for broader equidistribution phenomena in this setting, with concrete consequences for isogeny classes of abelian varieties over function fields.
Abstract
We investigate the analogue of the André--Pink--Zannier conjecture in characteristic $p$. Precisely, we prove it for ordinary function field-valued points with big monodromy, in Shimura varieties of Hodge type. We also prove an algebraic characteristic $p$ analogue of Hecke-equidistribution (as formulated by Mazur) for Shimura varieties of Hodge type. We prove our main results by a global and local analysis of prime-to-$p$ Hecke correspondences, and by showing that Weyl special points are abundant in positive characterstic.
