On varieties with Ulrich twisted tangent bundles

Abstract

We study varieties $X \subseteq \mathbb P^N$ of dimension $n$ such that $T_X(k)$ is an Ulrich vector bundle for some $k \in \mathbb Z$. First we give a sharp bound for $k$ in the case of curves. Then we show that $k \le n+1$ if $2 \le n \le 12$. We classify the pairs $(X,\mathcal O_X(1))$ for $k=1$ and we show that, for $n \ge 4$, the case $k=2$ does not occur.