A 2 - (v, k, 1) design D = (P,B) is a system consisting of a finite set P of v points and a collection B of k-subsets of P, called blocks, such that each 2-subset of P is contained in precisely one block.Let G be an a...A 2 - (v, k, 1) design D = (P,B) is a system consisting of a finite set P of v points and a collection B of k-subsets of P, called blocks, such that each 2-subset of P is contained in precisely one block.Let G be an automorphism group of a 2 - (v, k, 1) design. Delandtsheer proved that if G is block-primitive and D is not a projective plane, then G is almost simple, that is, T ≤ G ≤ Aut(T), where T is a non-abelian simple group. In this paper, we prove that T is not isomorphic to 3D4(q). This paper is part of a project to classify groups and designs where the group acts primitively on the blocks of the design.展开更多
This article is a contribution to the study of block-transitive automorphism groups of 2-(v,k,1) block designs. Let D be a 2-(v,k,1) design admitting a block-transitive, pointprimitive but not flag-transitive auto...This article is a contribution to the study of block-transitive automorphism groups of 2-(v,k,1) block designs. Let D be a 2-(v,k,1) design admitting a block-transitive, pointprimitive but not flag-transitive automorphism group G. Let kr = (k,v-1) and q = pf for prime p. In this paper we prove that if G and D are as above and q (3(krk-kr + 1)f)1/3, then G does not admit a simple group E6(q) as its socle.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.10171089).
文摘A 2 - (v, k, 1) design D = (P,B) is a system consisting of a finite set P of v points and a collection B of k-subsets of P, called blocks, such that each 2-subset of P is contained in precisely one block.Let G be an automorphism group of a 2 - (v, k, 1) design. Delandtsheer proved that if G is block-primitive and D is not a projective plane, then G is almost simple, that is, T ≤ G ≤ Aut(T), where T is a non-abelian simple group. In this paper, we prove that T is not isomorphic to 3D4(q). This paper is part of a project to classify groups and designs where the group acts primitively on the blocks of the design.
基金Supported by the National Natural Science Foundation of China (Grant No.10871205)China Postdoctoral Science Foundation Funded Project (Grant No.20080441323) Scientific Research Fund of Zhejiang Education Department (Grant No.Y200804780)
文摘This article is a contribution to the study of block-transitive automorphism groups of 2-(v,k,1) block designs. Let D be a 2-(v,k,1) design admitting a block-transitive, pointprimitive but not flag-transitive automorphism group G. Let kr = (k,v-1) and q = pf for prime p. In this paper we prove that if G and D are as above and q (3(krk-kr + 1)f)1/3, then G does not admit a simple group E6(q) as its socle.