Fano varieties with large pseudoindex and non-free rational curves
Abstract
For , let be a complex smooth Fano -fold whose minimal anticanonical degree of non-free rational curves on is at least . We classify extremal contractions of such varieties. As an application, we obtain a classification of Fano fourfolds with pseudoindex and Picard number greater than one. Combining this result with previous results, we complete the classification of smooth Fano -folds with pseudoindex at least and Picard number greater than one. This can be seen as a generalization of various previous results. We also discuss the relations between pseudoindex and other invariants of Fano varieties.
Keywords
Cite
@article{arxiv.2309.03438,
title = {Fano varieties with large pseudoindex and non-free rational curves},
author = {Kiwamu Watanabe},
journal= {arXiv preprint arXiv:2309.03438},
year = {2024}
}
Comments
27 pages. I have combined previous versions of this paper and paper arXiv:2402.14283 into this one paper. The content has been significantly revised, including the title and introduction