Invariant ideals and polynomial forms
Author:
D. S. Passman
Journal:
Trans. Amer. Math. Soc. 354 (2002), 33793408
MSC (2000):
Primary 16S34; Secondary 20F50, 20G05
Published electronically:
April 1, 2002
MathSciNet review:
1897404
Fulltext PDF Free Access
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Abstract: Let denote the group algebra of an infinite locally finite group . In recent years, the lattice of ideals of has been extensively studied under the assumption that is simple. From these many results, it appears that such group algebras tend to have very few ideals. While some work still remains to be done in the simple group case, we nevertheless move on to the next stage of this program by considering certain abelianby(quasisimple) groups. Standard arguments reduce this problem to that of characterizing the ideals of an abelian group algebra stable under the action of an appropriate automorphism group of . Specifically, in this paper, we let be a quasisimple group of Lie type defined over an infinite locally finite field , and we let be a finitedimensional vector space over a field of the same characteristic . If acts nontrivially on by way of the homomorphism , and if has no proper stable subgroups, then we show that the augmentation ideal is the unique proper stable ideal of when . The proof of this result requires, among other things, that we study characteristic division rings , certain multiplicative subgroups of , and the action of on the group algebra , where is the additive group . In particular, properties of the quasisimple group come into play only in the final section of this paper.
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Additional Information
D. S. Passman
Affiliation:
Department of Mathematics, University of Wisconsin, Madison, Wisconsin 53706
Email:
passman@math.wisc.edu
DOI:
http://dx.doi.org/10.1090/S0002994702030064
PII:
S 00029947(02)030064
Received by editor(s):
November 16, 2001
Published electronically:
April 1, 2002
Additional Notes:
Research supported in part by NSF Grant DMS9820271.
Dedicated:
Dedicated to Idun Reiten on the occasion of her $60$th birthday
Article copyright:
© Copyright 2002
American Mathematical Society
