Hostname: page-component-76fb5796d-2lccl Total loading time: 0 Render date: 2024-04-27T02:08:34.267Z Has data issue: false hasContentIssue false

On totally free crossed modules

Published online by Cambridge University Press:  18 May 2009

A. R.-Grandjean
Affiliation:
Departamento de Algebra, Universidad de Santiago, E-15771 Santiago de Compostela, Spain
M. Ladra
Affiliation:
Departamento de Algebra, Universidad de Santiago, E-15771 Santiago de Compostela, Spain
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In [10] we associate to a crossed module (T, G, მ) an invariant abelian crossed module H2(T, G, მ). The construction uses presentations by Set-free crossed modules. Now, Set-free crossed modules are special cases of totally free crossed modules, which are algebraic models of 2-dimensional CW complexes used by several authors (see [1] and [6]). The aim of this paper is to show that H2(T, G, მ) can also be constructed from presentations by arbitrary totally free crossed modules.

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 1998

References

REFERENCES

1.Baues, H. J., Combinatorial homotopy and 4-dimensional complexes, in Exp. Math., vol. 2, de Gruyter (Berlin/New York, 1991).Google Scholar
2.Brown, R. and Ellis, G. J., Hopf formulae for the higher homology of a group, Bull. London Math. Soc. 20 (1988), 124128.CrossRefGoogle Scholar
3.Brown, R. and Higgins, P. J., On the connection between the second relative homotopy groups of some related spaces, Proc. London Math. Soc.(3), 36 (1978), 193212.CrossRefGoogle Scholar
4.Brown, R. and Huebschmann, J., Identities among relations, in: Brown, R. and Thickstun, T. L., eds., Low-Dimensional topology, London Math. Soc. Lecture Note Series 48 (Cambridge Univ. Press, Cambridge, 1982), 153202.Google Scholar
5.Conduche, D. and Ellis, G. J., Quelques propriétés homologiques des modules précroisés, J. Algebra 123 (1989), 327335.CrossRefGoogle Scholar
6.Ellis, G. J., Homology of 2-Types, J. London Math. Soc. (2), 46 (1992), 127.CrossRefGoogle Scholar
7.Hilton, P. J. and Stammbach, U., A course in Homological Algebra (Springer, Berlin, 1971).CrossRefGoogle Scholar
8.Hopf, H., Fundamentalgruppe und sweite Bettische Gruppe, Comment. Math. Helvetici 14 (1941/1942), 257309.CrossRefGoogle Scholar
9.Ladra, M., Modulos Cruzados y Extensiones de Grupos, Ph. D. Thesis, Alxebra 39 (Universidad de Santiago de Compostela, 1984).Google Scholar
10.Ladra, M. and -Grandjeán, A. R., Crossed modules and homology, J. Pure Appl. Algebra 95 (1994), 4155.CrossRefGoogle Scholar
11.Norrie, K. J., Crossed Modules and analogues of Group theorems, Ph. D. Thesis, (University of London, 1987).Google Scholar
12.Norrie, K. J., The actor of a crossed module, U.C.N.W. Pure Maths Preprint 87.5, 1987.Google Scholar
13.Norrie, K. J., Actions and automorphisms of crossed Modules, Bull. Soc. Math. France 118 (1990), 129146.CrossRefGoogle Scholar
14.-Grandjeán, A. R., Homologíaen categorías exactas, Ph. D. Thesis, Alxebra 4, (Universidad de Santiago de Compostela, 1970).Google Scholar
15.Whitehead, J. H. C., Combinatorial Homotopy II, Bull. Amer. Math. Soc. 55 (1949), 453496.CrossRefGoogle Scholar