Rigidity of modular morphisms via Fujita decomposition
Algebraic Geometry
2025-07-23 v2
Abstract
In this note we prove that the Torelli, Prym and Spin-Torelli morphisms, as well as covering maps between moduli stacks of projective curves can not be deformed. The proofs use properties of the Fujita decomposition of the Hodge bundle of families of curves.
Keywords
Cite
@article{arxiv.2305.04525,
title = {Rigidity of modular morphisms via Fujita decomposition},
author = {Giulio Codogni and Víctor González-Alonso and Sara Torelli},
journal= {arXiv preprint arXiv:2305.04525},
year = {2025}
}
Comments
To appear on "Algebra & Number Theory"