On birational geometry of the space of parametrized rational curves in Grassmannians

Abstract

In this paper, we study the birational geometry of the Quot schemes of trivial bundles on ${\mathbb{P}}^1$ by constructing small $\mathbb{Q}$-factorial modifications of the Quot schemes as suitable moduli spaces. We determine all the models which appear in the minimal model program on the Quot schemes. As a corollary, we show that the Quot schemes are Mori dream spaces and log Fano.

22 pages, Remark 5.9 in v1 replaced by Lemma 5.11. Accordingly, Theorems 1.5, 1.6 changed