New 5-designs with automorphism group PSL(2, 23)
β Scribed by Masaaki Kitazume; Akihiro Munemasa
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 399 KB
- Volume
- 7
- Category
- Article
- ISSN
- 1063-8539
No coin nor oath required. For personal study only.
β¦ Synopsis
Blocks of the unique Steiner system S(5, 8, 24) are called octads octads octads. The group PSL(2, 23) acts as an automorphism group of this Steiner system, permuting octads transitively. Inspired by the discovery of a 5-(24, 10, 36) design by Gulliver and Harada, we enumerate all 4and 5-designs whose set of blocks are union of PSL(2, 23)-orbits on 10-subsets containing an octad.
π SIMILAR VOLUMES
## Abstract We determine the distribution of 3βdesigns among the orbits of 4β and 5βelement subsets under the action of PSL(2,2^__n__^) on the projective line. Thus we give complete information on all KramerβMesner matrices for the action of PSL(2,2^__n__^) on 3βsets versus 4β and 5βsets. As a cons
A t-vY kY k design is a set of v points together with a collection of its k-subsets called blocks so that all subsets of t points are contained in exactly k blocks. The d-dimensional projective geometry over GFqY PGdY q, is a 2 Γ q d q dΓ1 Γ Γ Γ q 1Y q 1Y 1 design when we take its points as the poin
In this paper we determine all symmetric designs with parameters (61,25,10) with an automorphism of order 5 fixing 11 points. Among them, there are exactly 24 non-isomorphic designs admitting the action of an elementary abelian group of order 25. The only previously known design with these parameter
## Abstract We determine the distribution of 3β(__q__ + 1,__k__,Ξ») designs, with __k__ Ο΅ {4,5}, among the orbits of __k__βelement subsets under the action of PSL(2,__q__), for __q__ Ο΅ 3 (mod 4), on the projective line. As a consequence, we give necessary and sufficient conditions for the existence
## Abstract In this article, we investigate the existence of large sets of 3βdesigns of prime sizes with prescribed groups of automorphisms PSL(2,__q__) and PGL(2,__q__) for __q__ < 60. We also construct some new interesting large sets by the use of the computer program DISCRETA. The results obtain