首页 | 本学科首页   官方微博 | 高级检索  
     


Simple birational extensions of the polynomial algebra
Authors:Shulim Kaliman   Sté  phane Vé    reau   Mikhail Zaidenberg
Affiliation:Department of Mathematics, University of Miami, Coral Gables, Florida 33124 ; Université Grenoble I, Institut Fourier, UMR 5582 CNRS-UJF, BP 74, 38402 St. Martin d'Hères cédex, France ; Université Grenoble I, Institut Fourier, UMR 5582 CNRS-UJF, BP 74, 38402 St. Martin d'Hères cédex, France
Abstract:The Abhyankar-Sathaye Problem asks whether any biregular embedding $varphi:mathbb{C}^khookrightarrowmathbb{C}^n$ can be rectified, that is, whether there exists an automorphism $alphain{operatorname{Aut}},mathbb{C}^n$ such that $alphacircvarphi$ is a linear embedding. Here we study this problem for the embeddings $varphi:mathbb{C}^3hookrightarrow mathbb{C}^4$ whose image $X=varphi(mathbb{C}^3)$ is given in $mathbb{C}^4$ by an equation $p=f(x,y)u+g(x,y,z)=0$, where $finmathbb{C}[x,y]backslash{0}$ and $ginmathbb{C}[x,y,z]$. Under certain additional assumptions we show that, indeed, the polynomial $p$ is a variable of the polynomial ring $mathbb{C}^{[4]}=mathbb{C}[x,y,z,u]$ (i.e., a coordinate of a polynomial automorphism of $mathbb{C}^4$). This is an analog of a theorem due to Sathaye (1976) which concerns the case of embeddings $mathbb{C}^2hookrightarrowmathbb{C}^3$. Besides, we generalize a theorem of Miyanishi (1984) giving, for a polynomial $p$ as above, a criterion for when $X=p^{-1}(0)simeqmathbb{C}^3$.

Keywords:Affine space   polynomial ring   variable   affine modification   birational extension.
点击此处可从《Transactions of the American Mathematical Society》浏览原始摘要信息
点击此处可从《Transactions of the American Mathematical Society》下载全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号