## Search

Now showing items 101-110 of 164

#### On some locally 3-transposition graphs

(1993)

Let ∑_n^ε be the graph defined on the (+)- points of an n-dimensional GF(3)-space carrying a nondegenerate symmetric bilinear form with discriminant ε, points are adjacent if they are perpendicular. We prove that if ε = ...

#### Williamson matrices and a conjecture of Ito's

(1999)

We point out an interesting connection between Williamson matrices and relative difference sets in nonabelian groups. As a consequence, we are able to show that there are relative (4t,2,4t,2t)-difference sets in the dicyclic ...

#### On transitive permutation groups with primitive subconstituents

(1999)

Let G be a transitive permutation group on a set Ω such that, for ω∈Ω, the stabiliser Gω induces on each of its orbits in Ω\{ω} a primitive permutation group (possibly of degree 1). Let N be the normal closure of Gω in G. ...

#### A new family of extended generalized quadrangles

(1997)

For every hyperovalOofPG(2,q) (qeven), we construct an extended generalized quadrangle with point-residues isomorphic to the generalized quadrangleT*2(O) of order(q-1, q+1).These extended generalized quadrangles are ...

#### Non-abelian representations of some sporadic geometries

(1996)

For a point-line incidence system S =(P, L) with three points per line we define the universal representation group of S asR(S)= ⟨zp, p∈P|zp^2=1 for p∈P,zp zq zr = 1 for {p,q,r} ∈ L⟩We prove that if G is the 2-local parabolic ...

#### Extended generalized octagons and the group He

(1995)

Let Γ be an extended generalized octagon such that the points of a triple {u, v, w} not on a block are pairwise adjacent if and only if the distance betweenv andw in the local generalized octagon Γu equals 3 and there is ...

#### Affine extensions of the Petersen graph and 2-arc-transitive graphs of girth 5

(1992)

Let Qn denote the set of the flag-transitive geometries with the diagram.
We construct examples of finite Qn-geometries for any n>= 2. This allows us to obtain new examples of finite 2-arc-transitive graphs of girth 5, ...

#### The extensions of the generalized quadrangle of order (3, 9)

(1996)

It is shown that there is only one extension of GQ(3, 9) namely the one admitting the sporadic simple groupMcL as a flag-transitive automorphism group. The proof depends on a computer calculation.

#### On (p^a,p^b,p^a,p^{a-b})-relative difference sets

(1996)

This paper provides new exponent and rank conditions for the existence of abelian relative (p^a,p^b,p^a,p^a-b) -difference sets. It is also shown that no splitting relative (2^2c,2^d,2^2c,2^2c-d)-difference set exists if ...

#### A local characterization of the graphs of alternating forms and the graphs of quadratic forms over GF(2)

(1993)

Let Δ be the line graph of PG(n –1,2), Alt(n,2) be the graph of the n-dimensional alternating forms over GF(2), n ≥ 4. Let Γ be a connected locally Δ graph such that 1. the number of common neighbours of any pair of vertices ...