×

Flag-transitive non-symmetric 2-designs with \((r,\lambda)=1\) and sporadic socle. (English) Zbl 1347.05019

Summary: This paper is a contribution to the investigation of flag-transitive non-symmetric 2-designs. We prove that if \(\mathcal {D}\) is a non-trivial non-symmetric 2-\((v,k,\lambda)\) design with \((r,\lambda)=1\) and \(G\leq \mathrm{Aut}(\mathcal {D})\) is flag-transitive with sporadic socle, then \(\mathcal {D}\) must be one of following: a 2-(12, 6, 5) design with \(G=M_{11}\), or a 2-(22, 6, 5) design with \(G=M_{22}\) or \(M_{22}:2\).

MSC:

05B05 Combinatorial aspects of block designs
05B25 Combinatorial aspects of finite geometries
20B25 Finite automorphism groups of algebraic, geometric, or combinatorial structures

Software:

Magma; GAP
Full Text: DOI

References:

[1] Bosma W., Cannon J., Playoust C.: The MAGMA algebra system I: the user language. J. Symb. Comput. 24, 235-265 (1997). · Zbl 0898.68039
[2] Bray J.N., Wilson R.A.: Explicit representations of the maximal subgroups of the Monster. J. Algebra 300(2), 834-857 (2006). · Zbl 1100.20019
[3] Buekenhout F., Delandtsheer A., Doyen J., Kleidman P.B., Liebeck M., Saxl J.: Linear spaces with flag-transitive automorphism groups. Geom. Dedicata 36, 89-94 (1990). · Zbl 0707.51017
[4] Camina A.R., Spiezia F.: Sporadic groups and automorphisms of linear spaces. J. Comb. Des. 8(5), 353-362 (2000). · Zbl 0974.20002
[5] Colbourn C.J., Dinitz J.H.: The CRC Handbook of Combinatorial Designs. CRC Press, Boca Raton (1996). · Zbl 0836.00010
[6] Conway J.H., Curtis R.T., Norton S.P., Parker R.A., Wilson R.A.: Atlas of Finite Groups. Oxford University Press, London (1985). · Zbl 0568.20001
[7] Davies H.: Flag-transitivity and primitivity. Discret. Math. 63, 91-93 (1987). · Zbl 0636.05008
[8] Davies H.: Automorphisms of Designs. Ph.D. Thesis, University of East Anglia (1987).
[9] Dembowski P.: Finite Geometries. Springer, New York (1968). · Zbl 0159.50001
[10] The GAP Group, GAP-Groups, Algorithms, and Programming, Version 4.4, 2005. http://www.gap-system.org
[11] Tian D., Zhou S.: Flag-transitive \[2-(v, k,\lambda )\](v,k,λ) symmetric designs with sporadic socle. J. Comb. Des. 23(4), 140-150 (2015). · Zbl 1310.05026
[12] Wielandt H.: Finite Permutation Groups. Academic Press, New York (1964). · Zbl 0138.02501
[13] Zhou S., Wang Y.: Flag-transitive non-symmetric 2-designs with \[(r,\lambda )=1\](r,λ)=1 and alternating socle. Electron. J. Comb. 22, #P2.6 (2015). · Zbl 1310.05040
[14] Zhu Y., Guan H., Zhou S.: Flag-transitive \[2-(v, k,\lambda )\](v,k,λ) symmetric designs with \[(r,\lambda )=1\](r,λ)=1 and alternating socle. Front. Math. China 10(6), 1483-1496 (2015). · Zbl 1325.05046
[15] Zieschang P.H.: Flag transitive automorphism groups of 2-designs with \[(r,\lambda )=1\](r,λ)=1. J. Algebra 118, 265-275 (1988). · Zbl 0661.20001
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.