Holomorphic forms and non-tautological cycles on moduli spaces of curves

Veronica Arena, Samir Canning, Emily Clader +4

We prove, for infinitely many values of $g$ and $n$, the existence of non-tautological algebraic cohomology classes on the moduli space ${\mathcal{M}}_{g,n}$ of smooth, genus-$g$, $n…