Differentiating Siegel modular forms, and the moving slope of ${\mathcal{A}}_g$

Samuel Grushevsky, Tomoyoshi Ibukiyama, Gabriele Mondello +1

We study the cone of moving divisors on the moduli space ${\mathcal{A}}_g$ of principally polarized abelian varieties. Partly motivated by the generalized Rankin-Cohen bracket, we c…