Urata's theorem in the logarithmic case and applications to integral points

Abstract

Urata showed that a pointed compact hyperbolic variety admits only finitely many maps from a pointed curve. We extend Urata’s theorem to the setting of (not necessarily compact) hyperbolically embeddable varieties. As an application, we show that a hyperbolically embeddable variety over a number field 𝐾 with only finitely many𝐿,𝑇-points for any number field 𝐿∕𝐾and any finite set of finite places 𝑇 of 𝐿 has, in fact, only finitely many points in any given ℤ-finitely generated integral domain of characteristic zero. We use this latter result in combination with Green’s criterion for hyperbolic embeddability to obtain novel finiteness results for integral points on symmetric self-products of smooth affine curves and on complements of large divisors in projective varieties. Finally, we use a partial converse to Green’s criterion to further study hyperbolic embeddability (or its failure) in the case of symmetric self-products of curves. As a by-product of our results, we obtain the first example of a smooth affine Brody-hyperbolic threefold over ℂ which is not hyperbolically embeddable.