Ulrich wildness of some decomposable threefold scrolls over ${\mathbb{F}}_a$

Maria Lucia Fania, Flaminio Flamini

The paper deals with Ulrich wildness of decomposable threefold scrolls $X$ over Hirzebruch surfaces ${\mathbb{F}}_a$, for any $a⩾0$. Our Main Theorem enstablishes that for…