Products of varieties with many integral points
Cedric Luger
TL;DR
This work generalizes the weak Hilbert property to arithmetic schemes via near-integral points and proves that WHP is stable under products, birational maps, and finite étale base changes. It develops arithmetic refinements and a Chevalley–Weil-type lifting for near-integral points to handle non-proper cases, and uses (PB)-covers and HIT to transfer WHP to connected algebraic groups. The main achievement is a positive verification of Corvaja–Zannier's arithmetic conjecture for all connected algebraic groups over finitely generated fields of characteristic zero. Together, these results deepen the understanding of thin sets and rational/near-integral point distribution on products and group schemes, with implications for related conjectures in arithmetic geometry.
Abstract
Corvaja and Zannier asked whether a smooth projective integral variety with a dense set of rational points over a number field satisfies the weak Hilbert property. We introduce an extension of the weak Hilbert property for schemes over arithmetic base rings by considering near-integral points, extending Corvaja-Zannier's question beyond the projective case. Building on work of Bary-Soroker-Fehm-Petersen and Corvaja-Demeio-Javanpeykar-Lombardo-Zannier, we prove several properties of this more general notion, in particular its persistence under products. We also answer positively Corvaja-Zannier's question for all algebraic groups over finitely generated fields of characteristic zero.
