The Automorphism Group of the Free Algebra of Rank Two
Serdica Mathematical Journal, Tome 28 (2002) no. 3, pp. 255-266
Cet article a éte moissonné depuis la source Bulgarian Digital Mathematics Library
The theorem of Czerniakiewicz and Makar-Limanov, that all
the automorphisms of a free algebra of rank two are tame is proved here by
showing that the group of these automorphisms is the free product of two
groups (amalgamating their intersection), the group of all affine automorphisms
and the group of all triangular automorphisms. The method consists
in finding a bipolar structure. As a consequence every finite subgroup of
automorphisms (in characteristic zero) is shown to be conjugate to a group of
linear automorphisms.
Keywords:
Free Algebra, Free Product with Amalgamation, Affine Automorphism, Linear Automorphism, Bipolar Structure
@article{SMJ2_2002_28_3_a6,
author = {Cohn, P.},
title = {The {Automorphism} {Group} of the {Free} {Algebra} of {Rank} {Two}},
journal = {Serdica Mathematical Journal},
pages = {255--266},
year = {2002},
volume = {28},
number = {3},
language = {en},
url = {http://geodesic.mathdoc.fr/item/SMJ2_2002_28_3_a6/}
}
Cohn, P. The Automorphism Group of the Free Algebra of Rank Two. Serdica Mathematical Journal, Tome 28 (2002) no. 3, pp. 255-266. http://geodesic.mathdoc.fr/item/SMJ2_2002_28_3_a6/