Fano schemes of complete intersections in toric varieties

Autor: Tyler L. Kelly, Nathan Ilten
Rok vydání: 2021
Předmět:
Zdroj: Mathematische Zeitschrift. 300:1529-1556
ISSN: 1432-1823
0025-5874
DOI: 10.1007/s00209-021-02809-4
Popis: We study Fano schemes $F_k(X)$ for complete intersections $X$ in a projective toric variety $Y\subset \mathbb{P}^n$. Our strategy is to decompose $F_k(X)$ into closed subschemes based on the irreducible decomposition of $F_k(Y)$ as studied by Ilten and Zotine. We define the expected dimension for these subschemes, which always gives a lower bound on the actual dimension. Under additional assumptions, we show that these subschemes are non-empty and smooth of the expected dimension. Using tools from intersection theory, we can apply these results to count the number of linear subspaces in $X$ when the expected dimension of $F_k(X)$ is zero.
Comment: 28 pages, minor revision, to appear in Math Z
Databáze: OpenAIRE