Let R be a 2-torsion free simple artinian ring with involution*. The element u of R is said to be unitary if u is invertible with inverse u*. In this paper we shall be concerned with the subalgebras W of R over its centre Z such that uWu* ⊆ W, for all unitaries u of R. We prove that if R has rank superior to 1 over a division ring D containing more than 5 elements and if R is not 4-dimensional then any such subalgebra W must be one of the trivial subalgebras 0, Z or R, under one of the following extra finiteness assumptions: W contains inverses, W satisfies a polynomial identity, the ground division ring D is algebraic, the involution is a conjugate-transpose involution such that D equipped with the induced involution is generated by unitaries.
@article{10_4153_CJM_1979_057_1,
author = {Chacron, M.},
title = {Unitaries in {Simple} {Artinian} {Rings}},
journal = {Canadian journal of mathematics},
pages = {542--557},
year = {1979},
volume = {31},
number = {3},
doi = {10.4153/CJM-1979-057-1},
url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1979-057-1/}
}
TY - JOUR
AU - Chacron, M.
TI - Unitaries in Simple Artinian Rings
JO - Canadian journal of mathematics
PY - 1979
SP - 542
EP - 557
VL - 31
IS - 3
UR - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1979-057-1/
DO - 10.4153/CJM-1979-057-1
ID - 10_4153_CJM_1979_057_1
ER -
%0 Journal Article
%A Chacron, M.
%T Unitaries in Simple Artinian Rings
%J Canadian journal of mathematics
%D 1979
%P 542-557
%V 31
%N 3
%U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1979-057-1/
%R 10.4153/CJM-1979-057-1
%F 10_4153_CJM_1979_057_1
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