The Suzuki Groups Sz(q)and 2-(v, k, 1) Designs

A 2-(v,k, l) design D=(Ω,B) is a system consisting of a finite set Ω of v points and acollection B of k-subsets of Ω, called blocks, such that any 2-subset of Ω is contained in exactlyone bled. We shall always assume that 2 < k < v.Let G S AutD be a group of automorphisms of a 2-(v, k, 1) design D. G is said to be blocktransitive (block primitive) on D if G is transitive (primitive, respectively) on B. G is said tobe point transitive (point primitive) on D if G is transitive (primiti…     

Suzuki群Sz(q)与2-(v,k,1)区组设计

§ 1　IntroductionA2 -( v,k,1 ) design D=( Ω,B) is a system consisting of a finite setΩ ofv points anda collection Bofk-subsets ofΩ ,called blocks,such thatany 2 -subsetofΩ is contained inexactly one block.We shall always assume that2 相似文献   

A Family of Non-quasiprimitive Graphs Constructed From PSU3（q） Where q Is Odd

Let Г be a simple connected graph and let G be a group of automorphisms of Г. Г is said to be （G, 2）-arc transitive if G is transitive on the 2-arcs of Г. It has been shown that there exists a family of non-quasiprimitive （PSU3（q）, 2）-arc transitive graphs where q = 2^3m with m an odd integer. In this paper we investigate the case where q is an odd prime power.     

SUZUKI GROUPS Sz（q） AND 2-（v,k, 1） BLOCK DESIGNS

It is proved that if D be a 2-(v,k,1) design with G≤Aut D block primitive then G does not have a Suzuki group Sz(q) as the socle.     

关于S.Axler的一个猜想的注记

In this note, we prove that a^p,q,a(0-1) is a self-con jugate spacl, so a^p ( =a^p,q,a) is self-conjugate, in other words, we prove that the conjecture of S. Axler istrue.     

Normal edge-transitive Cayley graphs on non-abelian groups of order 4p, where p is a prime number

We determine all connected normal edge-transitive Cayley graphs on non-abelian groups with order 4p,where p is a prime number.As a consequence we prove if |G|=2δp,δ=0,1,2 and p prime,then Γ=Cay(G,S) is a connected normal 1/2 arc-transitive Cayley graph only if G=F4p,where S is an inverse closed generating subset of G which does not contain the identity element of G and F 4p is a group with presentation F4p = a,b|ap=b4=1,b-1ab=aλ,where λ2≡-1(mod p).     

On a Supercongruence Conjecture of Z.-W. Sun

In this paper, the author partly proves a supercongruence conjectured by Z.-W.Sun in 2013. Let p be an odd prime and let a ∈ Z⁺. Then, if p ≡ 1 (mod 3),k=0 6p^a 2k k/16^k ≡ 3/p^a(modp²) is obtained, where is the Jacobi symbol.     

关于Cn空间有界域的一个解析不变量

The main results of the present paper are: For any bounded D in space Cⁿ, there is an analytic invariant λ(D)(≤1). If D is a transitive domain, then λ(D)<1 and k₀(D)=(λ(D))/(1-λ(D)), where k₀(D) is the Schwarz constant of domain D (cf[1]). And we have discussed the Characteristic properties of λ(D).     

A Characterization of a Class of Symmetric Graphs of Twice Prime Valency

Let г be a connected undirected graph aud G a group of automorphisms ofг.G is said to act symmetrically on г and г is said to be G-symmetric, if G istransitive on the set {(α,β) |α,β adjacent vertices} of 1-arcs of г. Thus G is tran-sitive on vertices and the stablizer G_a of a vertex a is transitive on the set г_1(a)     

区传递的$2-(v, k, 1)$ 设计与单群$E_6(q)$

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.     

Generalized quadrangles of order (q,q 2),q even,containingW(q) as a subquadrangle

In this paper we give a characterization of the generalized quadrangleQ(5,q),q even, in terms of ovoids of its subquadrangles.     

q -Bilattices

In the present paper, we consider the concepts of q-semilattices, q-lattices, and q-bilattices with unary operation and prove the existence of an epimorphism between q-bilattices of some varieties and the superproduct of two lattices.     

On (q 2 + q + 2, q + 2)-arcs in the Projective Plane PG(2, q)

A (k,n)-arc in PG(2,q) is usually defined to be a set of k points in the plane such that some line meets in n points but such that no line meets in more than n points. There is an extensive literature on the topic of (k,n)-arcs. Here we keep the same definition but allow to be a multiset, that is, permit to contain multiple points. The case k=q ²+q+2 is of interest because it is the first value of k for which a (k,n)-arc must be a multiset. The problem of classifying (q ²+q+2,q+2)-arcs is of importance in coding theory, since it is equivalent to classifying 3-dimensional q-ary error-correcting codes of length q ²+q+2 and minimum distance q ². Indeed, it was the coding theory problem which provided the initial motivation for our study. It turns out that such arcs are surprisingly rich in geometric structure. Here we construct several families of (q ²+q+2,q+2)-arcs as well as obtain some bounds and non-existence results. A complete classification of such arcs seems to be a difficult problem.     

A characterization of PGL(2,q),q ODD

LetG be a finite group andA andB solvable subgroups ofG, such thatG=AB and 2 is the only common prime divisor ofA andB. Under suitable restrictions of the 2-structure ofA andB, it is shown that eitherG is solvable orG contains a solvable normal subgroupN, such thatG/N contains a normal subgroup, which is isomorphic to PGL(2,q),q odd.     

A characterization of PGL(2, q), q odd

Following the lines of [10], we give a characterization of the group PGL(2, q), q odd, in terms of involutions.Work performed under the auspicies of G.N.S.A.C.A. of C.N.R. supported by the 40% grants of M.P.I.     

Designs from the Group PSL2(q), q Even

Let q be a power of 2 greater than 2 and consider the group G = PSL₂(q). We choose the maximal subgroups of G isomorphic to the dihedral groups D_2(q+1) and D_2(q-1) and present the primitive action of G on the right cosets of these two subgroups. We will find the orbits of the point stabilizer in each case and in the case of D_2(q-1) we will prove there is an orbit Δ of the point stabilizer G_ω, such that Δ ≠ {ω } and whose orbiting under G gives a 1-design with the automorphism group isomorphic to the symmetric group