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The group E6(q) and graphs with a locally linear group of automorphisms

Published online by Cambridge University Press:  24 August 2009

V. I. TROFIMOV
Affiliation:
Institute of Mathematics and Mechanics, Russian Academy of Sciences, Ural Branch, 620219 Ekaterinburg, Russia. e-mail: trofimov@imm.uran.ru
R. M. WEISS
Affiliation:
Department of Mathematics, Tufts University, Medford, MA 02155, U.S.A. e-mail: richard.weiss@tufts.edu

Abstract

Let q be a prime power and let G be a group acting faithfully and vertex transitively on a graph such that for each vertex x, the stabilizer Gx is finite and contains a normal subgroup inducing on the set of neighbours of x a permutation group isomorphic to the linear group L5(q) acting on the 2-dimensional subspaces of a 5-dimensional vector space over Fq. It is shown, except in some special situations where q = 2, that the kernel of the action of a vertex stabilizer Gx on the ball of radius 3 around x is trivial. (These special situations are eliminated in a companion paper by the first author.) An example coming from the exceptional group E6(q) shows that the kernel of the action of Gx on the ball of radius 2 around x can be non-trivial.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 2009

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References

REFERENCES

[1]Aschbacher, M.GF(2)-representations of finite groups. Amer. J. Math. 104 (1982), 683771.Google Scholar
[2]Bell, G.On the cohomology of the finite special linear groups, I–II. J. Algebra 54 (1978), 216259.CrossRefGoogle Scholar
[3]Chow, W. J.On the geometry of algebraic homogeneous spaces. Ann. Math. 50 (1949), 3267.Google Scholar
[4]Cooperstein, B.An enemies list for factorization theorems. Comm. Alg. 6 (1978), 12391288.CrossRefGoogle Scholar
[5]Gardiner, A.Arc transitivity in graphs II. Quart. J. Math. Oxford 25 (1974), 163167.Google Scholar
[6]McLaughlin, J.Some groups generated by transvections. Arch. Math. 18 (1967), 364368.Google Scholar
[7]McLaughlin, J.Some subgroups of SLn(F 2). Ill. J. Math. 13 (1969), 108115.Google Scholar
[8]Meixner, T.Failure of factorization modules for Lie-type groups in odd characteristic. Comm. Alg. 19 (1991), 31933222.Google Scholar
[9]Trofimov, V. I.Graphs with projective suborbits (in Russian). Izv. Akad. Nauk SSSR Ser. Mat. 55 (1991), no. 4, 890916; translation in Math. USSR-Izv. 39 (1992), no. 1, 869–893.Google Scholar
[10]Trofimov, V. I.Graphs with projective suborbits: cases of small characteristic, I–II (in Russian). Izv. Ross. Akad. Nauk Ser. Mat. 58 (1994), no. 5, 124171; 58 (1994), no. 6, 137–156; translations in Russian Acad. Sci. Izv. Math. 45 (1995), no. 2, 353–398; 45 (1995), no. 3, 559–576.Google Scholar
[11]Trofimov, V. I.Graphs with projective suborbits: exceptional cases of characteristic 2, I–IV (in Russian). Izv. Ross. Akad. Nauk Ser. Mat. 62 (1998), no. 6, 159222; 64 (2000), no. 1, 175–196; 65 (2001), no. 4, 151–190; 67 (2003), no. 6, 193–222; translations in Izv. Math. 62 (1998), no. 6, 1221–1279; 64 (2000), no. 1, 173–192; 65 (2001), no. 4, 787–822; 67 (2003), no. 6, 1267–1294.Google Scholar
[12]Trofimov, V. I. Supplement to “The group E 6(q) and graphs with a locally linear group of automorphisms” by V. I. Trofimov and R. M. Weiss. Math. Proc. Cambridge Phil. Soc., this issue.Google Scholar
[13]Trofimov, V. I. and Weiss, R. M.Graphs with a locally linear group of automorphisms. Math. Proc. Cambridge Phil. Soc. 118 (1995), 191206.Google Scholar
[14]Tutte, W. T.A family of cubical graphs. Proc. Camb. Phil. Soc. 43 (1947), 459474; on the symmetry of cubic graphs. Canad. J. Math. 11 (1959), 621–624.Google Scholar
[15]Weiss, R. M.Symmetric graphs with projective subconstituents. Proc. Amer. Math. Soc. 72 (1978), 213217.Google Scholar
[16]Weiss, R. M.Graphs which are locally Grassmann. Math. Ann. 297 (1993), 325334.CrossRefGoogle Scholar