Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-27T22:16:09.282Z Has data issue: false hasContentIssue false

Covering groups with subgroups

Published online by Cambridge University Press:  17 April 2009

R.A. Bryce
Affiliation:
School of Mathematical Sciences, The Australian National University, Canberra ACT 0200, Australia
V. Fedri
Affiliation:
School of Mathematical Sciences, The Australian National University, Canberra ACT 0200, Australia
L. Serena
Affiliation:
Dipartimento di Matematica, viale Morgagni 67/A, 50134 Firenze, Italia
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.

A group is covered by a collection of subgroups if it is the union of the collection. The intersection of an irredundant cover of n subgroups is known to have index bounded by a function of n, though in general the precise bound is not known. Here we confirm a claim of Tompkinson that the correct bound is 16 when n is 5. The proof depends on determining all the ‘minimal’ groups with an irredundant cover of five maximal subgroups.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1997

References

[1]Bryce, R.A., Fedri, V. and Serena, L., ‘A Hughes-like property for finite groups’, Proc. Edinburgh Math. Soc. (2) 38 (1995), 533541.CrossRefGoogle Scholar
[2]Doerk, K. and Hawkes, T., Finite soluble groups (Walter de Gruyter, Berlin, New York, 1992).CrossRefGoogle Scholar
[3]Greco, D., ‘Su alcuni gruppi finit che sono somma di cinque sottogruppi’, Rend. Sem. Mat. Univ. Padova 22 (1953), 313333.Google Scholar
[4]Greco, D., ‘Sui gruppi che sono somma di quattro o cinque sottogruppi’, Rend. Accad. Sci. Fis. Mat. Napoli (4) 23 (1956), 4959.Google Scholar
[5]Neumann, B.H., ‘Groups covered by finitely many cosets’, Publ. Math. Debrecen 3 (1954), 227242.CrossRefGoogle Scholar
[6]Scorza, G., ‘I gruppi che possono pensarsi come somma di tre loro sottogruppi’, Boll. Un. Mat. Ital. 5 (1926), 216218.Google Scholar
[7]Tomkinson, M.J., ‘Groups covered by finitely many cosets or subgroups’, Comm. Algebra 15 (1987), 845859.CrossRefGoogle Scholar