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arXiv 0810.4195math.AG
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等平凡纤维化的数值性质

Numerical properties of isotrivial fibrations

Francesco Polizzi

摘要:

本文研究了相对极小等平凡纤维化$φ\colon X \lr C$的数值性质,其中$X$是光滑的射影曲面,$C$是曲线.特别是,我们证明,如果$g(C) \geq 1$和$X$既不规则,也不同构于一个拟丛,那么$K_X^2 \leq 8 χ(\mO_X)-2$ ;这个不等式是尖锐的,如果平等举行,然后$X$是一个极小曲面的一般类型的正则模型有两个普通的二重点作为奇点。在进一步假设$K_X$是充分的条件下,得到了$K_X^2 \leq 8 χ(\mO_X)-5$,并且该不等式也是尖锐的.这改进了Serrano和Tan以前的结果。

英文摘要:

In this paper we investigate the numerical properties of relatively minimal isotrivial fibrations $φ\colon X \lr C$, where $X$ is a smooth, projective surface and $C$ is a curve. In particular we prove that, if $g(C) \geq 1$ and $X$ is neither ruled nor isomorphic to a quasi-bundle, then $K_X^2 \leq 8 χ(\mO_X)-2$; this inequality is sharp and if equality holds then $X$ is a minimal surface of general type whose canonical model has precisely two ordinary double points as singularities. Under the further assumption that $K_X$ is ample, we obtain $K_X^2 \leq 8 χ(\mO_X)-5$ and the inequality is also sharp. This improves previous results of Serrano and Tan.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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