Isotype subgroups of mixed groups
Commentationes Mathematicae Universitatis Carolinae, Tome 42 (2001) no. 3, pp. 421-442
In this paper, we initiate the study of various classes of isotype subgroups of global mixed groups. Our goal is to advance the theory of $\Sigma$-isotype subgroups to a level comparable to its status in the simpler contexts of torsion-free and $p$-local mixed groups. Given the history of those theories, one anticipates that definitive results are to be found only when attention is restricted to global $k$-groups, the prototype being global groups with decomposition bases. A large portion of this paper is devoted to showing that primitive elements proliferate in $\Sigma$-isotype subgroups of such groups. This allows us to establish the fundamental fact that finite rank $\Sigma$-isotype subgroups of $k$-groups are themselves $k$-groups.
In this paper, we initiate the study of various classes of isotype subgroups of global mixed groups. Our goal is to advance the theory of $\Sigma$-isotype subgroups to a level comparable to its status in the simpler contexts of torsion-free and $p$-local mixed groups. Given the history of those theories, one anticipates that definitive results are to be found only when attention is restricted to global $k$-groups, the prototype being global groups with decomposition bases. A large portion of this paper is devoted to showing that primitive elements proliferate in $\Sigma$-isotype subgroups of such groups. This allows us to establish the fundamental fact that finite rank $\Sigma$-isotype subgroups of $k$-groups are themselves $k$-groups.
Classification :
20K21, 20K27
Keywords: global $k$-group; $\Sigma$-isotype subgroup; $\ast$-isotype subgroup; knice subgroup; primitive element; $\ast$-valuated coproduct
Keywords: global $k$-group; $\Sigma$-isotype subgroup; $\ast$-isotype subgroup; knice subgroup; primitive element; $\ast$-valuated coproduct
@article{CMUC_2001_42_3_a0,
author = {Megibben, Charles and Ullery, William},
title = {Isotype subgroups of mixed groups},
journal = {Commentationes Mathematicae Universitatis Carolinae},
pages = {421--442},
year = {2001},
volume = {42},
number = {3},
mrnumber = {1859590},
zbl = {1102.20037},
language = {en},
url = {http://geodesic.mathdoc.fr/item/CMUC_2001_42_3_a0/}
}
Megibben, Charles; Ullery, William. Isotype subgroups of mixed groups. Commentationes Mathematicae Universitatis Carolinae, Tome 42 (2001) no. 3, pp. 421-442. http://geodesic.mathdoc.fr/item/CMUC_2001_42_3_a0/