摘要翻译:
我们证明了对于K[x,y,z]$中的多项式$f\$等价是:(1)$f$是$k[z][x,y]$的$k[z]$-坐标,(2)$k[x,y,z]/(f)\cong k^{[2]}$和$f(x,y,a)$是$k[x,y]$中的坐标。这解决了Abhyankar-Sathaye猜想的一个特例。因此,我们看到在k[x,y,z]$中的坐标$F\,也是$k(z)$-坐标,是$k[z]$-坐标。我们讨论了一种构造$k[x,y,z]$自同构的方法,并观察到Nagata自同构自然地出现为通过这种方法得到的第一个非平凡自同构--本质上是将Nagata与$r[x]$的非驯服的$r$-自同构联系起来,其中$r=k[z]/(z^2)$。
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英文标题:
《A note on k[z]-automorphisms in two variables》
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作者:
Eric Edo, Arno van den Essen, Stefan Maubach
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最新提交年份:
2008
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分类信息:
一级分类:Mathematics 数学
二级分类:Commutative Algebra 交换代数
分类描述:Commutative rings, modules, ideals, homological algebra, computational aspects, invariant theory, connections to algebraic geometry and combinatorics
交换环,模,理想,同调代数,计算方面,不变理论,与代数几何和组合学的联系
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一级分类:Mathematics 数学
二级分类:Algebraic Geometry 代数几何
分类描述:Algebraic varieties, stacks, sheaves, schemes, moduli spaces, complex geometry, quantum cohomology
代数簇,叠,束,格式,模空间,复几何,量子上同调
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英文摘要:
We prove that for a polynomial $f\in k[x,y,z]$ equivalent are: (1)$f$ is a $k[z]$-coordinate of $k[z][x,y]$, and (2) $k[x,y,z]/(f)\cong k^{[2]}$ and $f(x,y,a)$ is a coordinate in $k[x,y]$ for some $a\in k$. This solves a special case of the Abhyankar-Sathaye conjecture. As a consequence we see that a coordinate $f\in k[x,y,z]$ which is also a $k(z)$-coordinate, is a $k[z]$-coordinate. We discuss a method for constructing automorphisms of $k[x,y,z]$, and observe that the Nagata automorphism occurs naturally as the first non-trivial automorphism obtained by this method - essentially linking Nagata with a non-tame $R$-automorphism of $R[x]$, where $R=k[z]/(z^2)$.
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PDF链接:
https://arxiv.org/pdf/0809.0767


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