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The geometric realization of Wall obstructions by nilpotent and simple spaces

Published online by Cambridge University Press:  24 October 2008

Guido Mislin
Affiliation:
ETH-Z, 8092 Zürich

Extract

Let π denote a finite group. It is well known that every element of the projective class group K0 ℤπ may be realized as Wall obstruction of a finitely dominated complex with fundamental group π (cf. (13)). We will study two subgroups N0ℤπ and Nℤπ of K0ℤπ, which are closely related to the Wall obstruction of nilpotent spaces. If the group π is nilpotent and if S denotes the set of elements xK0ℤπ which occur as Wall obstructions of nilpotent spaces, then

It turns out that in many instances one has N0,ℤπ = Nℤπ (cf. Section 3) and one obtains hence new information on S. The main theorem (2·4) provides a systematic way of constructing finitely dominated nilpotent (or even simple) spaces with non-vanishing Wall obstructions.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1980

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References

REFERENCES

(1)Fröhlich, A.On the class group of integral group rings of finite abelian groups. I. Mathematika. 16 (1969), 143152.CrossRefGoogle Scholar
(2)Fröhlich, A., Keating, M. E. and Wilson, S. M. J.The class groups of quaternion and dihedral 2-groups. Mathematika 21 (1974), 6471.CrossRefGoogle Scholar
(3)Hilton, P., Mislin, G., Roitberg, J. and Steiner, R.On free maps and free homotopies into nilpotent spaces. Springer Lecture Notes in Math. Vol. 673, 1977.Google Scholar
(4)Mislin, G.Finitely dominated nilpotent spaces. Ann. of Math. 103 (1976), 547556.CrossRefGoogle Scholar
(5)Mislin, G.Groups with cyclic Sylow subgroups and finiteness conditions for certain complexes. Comment. Math. Helv. 52 (1977), 373391.CrossRefGoogle Scholar
(6)Mislin, G.Finitely dominated complexes with metacyclic fundamental groups. Topology and Algebra, Proceedings of a Colloquium in honour of B. Eckmann, Monographie No. 26, L'Enseignement Mathématique 1978, 233235.Google Scholar
(7)Mislin, G. and Varadarajan, K.The finiteness obstruction for nilpotent spaces lie in D(ℤπ). Inventiones math. 53 (1979), 185191.CrossRefGoogle Scholar
(8)Rim, D. S.Modules over finite groups. Ann. of Math. 63 (1959), 700712.CrossRefGoogle Scholar
(9)Swan, R. G.Periodic resolutions for finite groups. Ann. of Math. 72 (1960), 267291.CrossRefGoogle Scholar
(10)Taylor, M. J.Locally free class groups of prime power order. J. Algebra 50 (1978), 463487.CrossRefGoogle Scholar
(11)Ullom, S. V.Nontrivial lower bounds for class groups of integral group rings. Illinois J. of Math. 20 (1976), 361371.CrossRefGoogle Scholar
(12)Varadarajan, K.Finiteness obstructions for nilpotent spaces. J. Pure and Appl. Algebra 12 (1978), 137146.CrossRefGoogle Scholar
(13)Wall, C. T. C.Finiteness conditions for CW-complexes. Ann. of Math. 81 (1965), 5669.CrossRefGoogle Scholar