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arXiv 1702.06010math.AG
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关于可分高次Gauss映射

On separable higher Gauss maps

Katsuhisa Furukawa, Atsushi Ito

摘要:

本文研究了F.~意义下的$m$阶高斯映射L.~代数闭域上的射影簇$X \subset \mathbb{P}^N$的Zak。对所有具有$n:=\dim(X) \leq m < N$的整数$m$,证明了当$m$阶Gauss映射可分时,一般切$m$ -平面在$X$上的接触轨迹是线性簇.我们还证明了,对于光滑的$X$与$n < N-2$,$(n+1)$ -th高斯映射是双有理的,如果它是可分的,除非$X$是Segre嵌入$\mathbb{P}^1 \times \mathbb{P}^n \subset \mathbb{P}^{2n-1}$。这与L有关。Ein对特征为零的小对偶品种的分类。

英文摘要:

We study the $m$-th Gauss map in the sense of F.~L.~Zak of a projective variety $X \subset \mathbb{P}^N$ over an algebraically closed field in any characteristic. For all integer $m$ with $n:=\dim(X) \leq m < N$, we show that the contact locus on $X$ of a general tangent $m$-plane is a linear variety if the $m$-th Gauss map is separable. We also show that for smooth $X$ with $n < N-2$, the $(n+1)$-th Gauss map is birational if it is separable, unless $X$ is the Segre embedding $\mathbb{P}^1 \times \mathbb{P}^n \subset \mathbb{P}^{2n-1}$. This is related to L. Ein's classification of varieties with small dual varieties in characteristic zero.

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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