On O'Grady's generalized Franchetta conjecture

Nebojsa Pavic, Junliang Shen, Qizheng Yin

We study relative zero cycles on the universal polarized $K3$ surface $X\to {\mathcal{F}}_g$ of degree $2g-2$. It was asked by O'Grady if the restriction of any class in $\mathrm{…