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Groupings of Metabelian Groups and Extension Categories

Published online by Cambridge University Press:  20 November 2018

K. W. Roggenkamp*
Affiliation:
Universität Stuttgart, Stuttgart, West Germany
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Let G be a metabelian group and R an integral domain of characteristic zero, such that no rational prime divisor of │G│ is invertible in R. By RG we denote the group ring of G over R. In this note we shall prove

THEOREM. If RGRH as R-algebras, then GH

The question whether this result holds was posed to me by S. K. Sehgal. The result for R = Z is contained in G. Higman's thesis, and he apparently also proved a more general result. At any rate, I think that the methods of the proof are interesting eo ipso, since they establish a “Noether-Deuring theorem” for extension categories.

In proving the above result, it is necessary to study closely the category of extensions (ℊs, S), where the objects are short exact sequences of SG-modules

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1980

References

1. Geyer, W.-D., Galois groups of intersections of local fields, Israel J. Math. (1978).Google Scholar
2. Gruenberg, K. W., Cohomological topics in group theory, Springer LN 143 (1970).Google Scholar
3. Gruenberg, K. W. and Roggenkanip, K. W., Extension categories I, J. Algebra 49 (1977), 564594.Google Scholar
4. Gruenberg, K. W. and Roggenkanip, K. W., Extension categories II, to appear, in J. Algebra.Google Scholar
5. Hilbert, D., Uber die Irreduzibilitat ganzer rationaler Funktionen mit ganzzahligen Koeffizienten, J.f.d.r.u. angew. Math., Bd. 110 (1892), 104129.Google Scholar
6. Higman, G., The units of group rings, Proc. London Math. Soc. (2) 46 (1940), 231248.Google Scholar
7. Nagata, M., Local rings (Interscience, John Wiley, 1962).Google Scholar
8. Roggenkanip, K. W. An extension of the ∼No ether-Dewing theorem, Proc. Am. Math. Soc. 31 (1972), 423426.Google Scholar
9. Roggenkamp, K. W. and Huber-Dyson, V., Lattices over orders I, Springer LN 115 (1970).Google Scholar
10. Sehgal, S. K., On the isomorphism of integral group rings I, II, Can. J. Math. 21 (1969), 410413;1182-1188.Google Scholar