Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-23T10:56:00.175Z Has data issue: false hasContentIssue false

Fusion of 2-elements in groups of finite Morley rank

Published online by Cambridge University Press:  12 March 2014

Luis-Jaime Corredor*
Affiliation:
Universidad De Los Andes, Departamento De Matematicas, Santafe De Bogota, D.C., A.A. 4976, Colombia, E-mail: [email protected]

Extract

The Alperin-Goldschmidt Fusion Theorem [1, 5], when combined with pushing up [7], was a useful tool in the classification of the finite simple groups. Similar theorems are needed in the study of simple groups of finite Morley rank, in the even type case (that is, when the Sylow 2-subgroups are of bounded exponent, as in algebraic groups over fields of characteristic 2). In that context a body of results relating to fusion of 2-elements and the structure of 2-local subgroups is needed: pushing up, and the classification of groups with strongly or weakly embedded subgroups, or have strongly closed abelian subgroups (c.f, [2]). Two theorems of Alperin-Goldschmidt type are proved here. Both are needed in applications.

The following is an exact analog of the Alperin-Goldschmidt Fusion Theorem for groups of finite Morley rank, in the case of 2-elements:

Theorem 1.1. Let G be a group of finite Morley rank, and P a Sylow 2-subgroup of G. If A, BP are conjugate in G, then there are subgroups HiPand elementsxiN(Hi) for 1 ≤ in, and an elementyN(P), such that for all i:

1. Hi is a tame intersection of two Sylow 2-subgroups;

2. CP(Hi) ≤ Hi;

3. N(Hi)/Hiis 2-isolated

and

(a)

(b) .

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Alperin, J. L., Sylow intersections and fusion, Journal of Algebra, vol. 6 (1967), pp. 222241.CrossRefGoogle Scholar
[2]Borovik, A. V.. Tame groups of odd and even type, Algebraic groups and their representations (Carter, R. W. and Saxl, J., editors), NATO ASI series C: Mathematical and Physical Sciences, Kluwer Academic Publishers, Dordrecht, 1998, pp. 341366.CrossRefGoogle Scholar
[3]Borovik, A. V. and Nesin, A., Groups of finite Morley rank, Oxford University Press, Oxford, 1994.CrossRefGoogle Scholar
[4]Borovik, A. V. and Poizat, B., Tores etp-groups, this Journal, vol. 55 (1990), pp. 478491.Google Scholar
[5]Goldschmidt, D. M., A conjugation family for finite groups, Journal of Algebra, vol. 16 (1970), pp. 138142.CrossRefGoogle Scholar
[6]Pillay, A., Morley degree in groups of finite Morley rank and finite-dimensional theories, preprint.Google Scholar
[7]Stellmacher, B., Pushing up, Archives of Mathematics, vol. 46 (1986), pp. 817.CrossRefGoogle Scholar
[8]Suzuki, M., Group Theory I, translation of Gunron I (Japanese), Springer, New York, 1982.Google Scholar