Hyperbolicity properties of moduli spaces of marked hyperk{ä}hler manifolds
Bastien Philippe
TL;DR
The paper investigates hyperbolicity phenomena for moduli spaces of marked hyperkähler manifolds by focusing on deformations along directions with positive Hodge-bundle curvature. It develops a lifting framework that realizes prescribed period maps from arbitrary curves into the period domain and then into the moduli space, extending prior results to higher dimensions and noncompact base curves. By analyzing 2-dimensional K3-type period domains and employing Nevanlinna theory, it derives a vanishing result for the positive Kobayashi pseudo-distance on the moduli space when the marking lattice has rank at least 4 and provides jet-analytic restrictions on entire curves in period domains. The work connects period-domain geometry, MBM/class-wall structures, and complex-analytic techniques to constrain families of hyperkähler manifolds and their moduli, with implications for directed hyperbolicity and period-map dynamics.
Abstract
We study the hyperbolicity properties of moduli spaces of marked hyperk{ä}hler manifolds along directions corresponding to families having positivity properties for their Hodge bundle. In particular, we show that the Kobayashi pseudo-distance computed using disks tangent to these directions vanishes. As an intermediate step, we establish the existence of families of marked hyperk{ä}hler manifolds over arbitrary curves having a prescribed period map to the corresponding period domain. This generalizes a recent theorem of Greb and Schwald [GS24] to the case of hyperk{ä}hler manifolds of arbitrary dimensions and nonnecessarily compact curves. Finally, using Nevanlinna theory, we establish restrictions on families of hyperk{ä}hler manifolds over C having positive Hodge bundle.
