Now showing items 1-4 of 4

• #### A Characterization of Semisimple Plane Polynomial Automorphisms ﻿

[OWP-2008-08] (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 McKay-conjecture for exceptional groups and odd primes ﻿

[OWP-2007-07] (Mathematisches Forschungsinstitut Oberwolfach, 2007)
Let $\mathbf{G}$ be a simply-connected simple algebraic group over an algebraically closed field of characteristic p with a Frobenius map $F:\mathbf{G}→\mathbf{G}$ and $\mathbf{G}:=\mathbf{G}^F$, such that the root system ...
• #### The Nagata automorphism is shifted linearizable ﻿

[OWP-2008-09] (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] (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 ...