• 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 GLn(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] Späth, Britta (Mathematisches Forschungsinstitut Oberwolfach, 2007)
      Let G be a simply-connected simple algebraic group over an algebraically closed field of characteristic p with a Frobenius map F:GG and G:=GF, such that the root system ...
    • 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:=(XYΔZΔ2,Y+ZΔ,Z) where Δ=XZ+Y2 ...
    • 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 fk[x,y,z] equivalent are: (1)f is a k[z]-coordinate of k[z][x,y], and (2) k[x,y,z]/(f)k[2] and f(x,y,a) is a coordinate in k[x,y] for some ak. This solves ...