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ID 33221
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Author
Danchev, Peter
Abstract

Let F be a field of char(F) = p > 0 and G an abelian group with p-component Gp of cardinality at most ℵ1 and length at most ω1. The main affirmation on the Direct Factor Problem is that S(FG)/Gp is totally projective whenever F is perfect. This extends results due to May (Contemp. Math., 1989) and Hill-Ullery (Proc. Amer. Math. Soc., 1990). As applications to the Isomorphism Problem, suppose that for any group H the F-isomorphism FH ≅ FG holds. Then if Gp is totally projective, Hp ≅ Gp. This partially solves a problem posed by May (Proc. Amer. Math. Soc., 1988). In particular, H ≅ G provided G is p-mixed of torsion-free rank one so that Gp is totally projective. The same isomorphism H ≅ G is fulfilled when G is p-local algebraically compact too. Besides if Fp is the simple field with p-elements and Gp FpH is a coproduct of torsion complete groups, FpH ≅ FpG as Fp Fp-algebras implies Hp ≅ Gp. This expands the central theorem obtained by us in (Rend. Sem. Mat. Univ. Padova, 1999) and partly settles the generalized version of a question raised by May (Proc. Amer. Math. Soc.,1979) as well. As a consequence, when Gp is torsion complete and G is p-mixed of torsion-free rank one, H ≅ G. Moreover, if G is a coproduct of p-local algebraically compact groups then H ≅ G. The last attainment enlarges an assertion of Beers-Richman-Walker (Rend. Sem. Mat. Univ. Padova, 1983). Each of the reported achievements strengthens our statements in this direction (Southeast Asian Bull. Math., 2001-2002) and also continues own studies in this aspect (Hokkaido Math. J., 2000) and (Kyungpook Math. J., 2004).

Published Date
2009-01
Publication Title
Mathematical Journal of Okayama University
Volume
volume51
Issue
issue1
Publisher
Department of Mathematics, Faculty of Science, Okayama University
Start Page
179
End Page
192
ISSN
0030-1566
NCID
AA00723502
Content Type
Journal Article
language
英語
File Version
publisher
Refereed
True
Submission Path
mjou/vol51/iss1/13
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