Browsing 2008 by MFO Scientific Program "OWLF 2007"

Now showing items 1-3 of 3

A Characterization of Semisimple Plane Polynomial Automorphisms

[OWP-2008-08] Maubach, Stefan; Furter, Jean-Philippe (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-12)

It is well-known that an element of the linear group $GL_n(\mathbb{C})$ is semisimple if and only if its conjugacy class is Zariski closed. The aim of this paper is to show that the same result holds for the group of complex ...
The Nagata automorphism is shifted linearizable

[OWP-2008-09] Maubach, Stefan; Poloni, Pierre-Marie (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-13)

A polynomial automorphism $F$ is called shifted linearizable if there exists a linear map $L$ such that $LF$ is linearizable. We prove that the Nagata automorphism $N:= (X-Y\Delta-Z\Delta^2,Y+Z\Delta,Z)$ where $\Delta=XZ+Y^2$ ...
A note on k[z]-Automorphisms in Two Variables

[OWP-2008-17] Edo, Eric; Essen, Arno van den; Maubach, Stefan (Mathematisches Forschungsinstitut Oberwolfach, 2008)

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 ...