English

Tautological modular forms of level two and degree two

Algebraic Geometry 2026-05-14 v1 Number Theory

Abstract

We show how to use divisors on the projectivized Hodge bundle to construct special vector-valued modular forms and then apply invariant theory to construct all vector-valued Siegel modular forms of level two and degree two. Thus we construct all modular forms in terms of certain basic modular forms that are intimately connected to the moduli of curves of genus two.

Keywords

Cite

@article{arxiv.2605.13300,
  title  = {Tautological modular forms of level two and degree two},
  author = {Fabien Cléry and Gerard van der Geer},
  journal= {arXiv preprint arXiv:2605.13300},
  year   = {2026}
}

Comments

22 pages

R2 v1 2026-07-22T07:09:47.254Z