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Bibliographic Details
Main Author: Yuan, Yao
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2412.10013
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author Yuan, Yao
author_facet Yuan, Yao
contents Let $X$ be a projective smooth surface over $\mathbb{C}$ with $H^2(\mathcal{O}_X)=0$. Let $M=M(L,χ)$ be the moduli space of 1-dimensional semistable sheaves with determinant $\mathcal{O}_X(L)$ and Euler characteristic $χ$. We have the Hilbert-Chow morphism $π:M\rightarrow |L|$. We give explicit forms of the higher direct images $R^iπ_*\mathcal{O}_M$ under some mild conditions on $M$ and $|L|$. Our result shows that $R^iπ_*\mathcal{O}_M$ are direct sums of line bundles. In particular, using our result one gets explicit formulas for the Euler characteristic of $π^*\mathcal{O}_{|L|}(m)$, which in $X=\mathbb{P}^2$ case was once conjectured by Chung-Moon.
format Preprint
id arxiv_https___arxiv_org_abs_2412_10013
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Higher direct images of the structure sheaf via the Hilbert-Chow morphism
Yuan, Yao
Algebraic Geometry
14D22, 14J26
Let $X$ be a projective smooth surface over $\mathbb{C}$ with $H^2(\mathcal{O}_X)=0$. Let $M=M(L,χ)$ be the moduli space of 1-dimensional semistable sheaves with determinant $\mathcal{O}_X(L)$ and Euler characteristic $χ$. We have the Hilbert-Chow morphism $π:M\rightarrow |L|$. We give explicit forms of the higher direct images $R^iπ_*\mathcal{O}_M$ under some mild conditions on $M$ and $|L|$. Our result shows that $R^iπ_*\mathcal{O}_M$ are direct sums of line bundles. In particular, using our result one gets explicit formulas for the Euler characteristic of $π^*\mathcal{O}_{|L|}(m)$, which in $X=\mathbb{P}^2$ case was once conjectured by Chung-Moon.
title Higher direct images of the structure sheaf via the Hilbert-Chow morphism
topic Algebraic Geometry
14D22, 14J26
url https://arxiv.org/abs/2412.10013