This paper concerns finite, edge-transitive direct and strong products, as well as infinite weak Cartesian products. We prove that the direct product of two connected, non-bipartite graphs is edge-transitive if and only if both factors are edgetransitive and at least one is arc-transitive, or one factor is edge-transitive and the other is a complete graph with loops at each vertex. Also, a stro...

In this paper, a complete classification of finite simple cubic vertex-transitive graphs girth 6 is obtained. It proved that every such graph, with the exception Desargues graph on 20 vertices, either skeleton hexagonal tiling torus, truncation an arc-transitive triangulation closed hyperbolic surface, or 6-regular respect to dihedral scheme. Cubic larger than are also discussed.

A non-complete graph Γ is said to be (G, 2)-distance-transitive if, for i = 1, 2 and for any two vertex pairs (u1, v1) and (u2, v2) with dΓ(u1, v1) = dΓ(u2, v2) = i, there exists g ∈ G such that (u1, v1) = (u2, v2). This paper classifies the family of (G, 2)-distancetransitive graphs of valency 6 which are not (G, 2)-arc-transitive.

A description is given of finite permutation groups containing a cyclic regular subgroup. It is then applied to derive a classification of arc transitive circulants, completing the work dating from 1970’s. It is shown that a connected arc transitive circulant of order n is one of the following: a complete graph Kn , a lexicographic product [K̄b], a deleted lexicographic product [K̄b] − b , where ...

Abstract A graph is edge-primitive if its automorphism group acts primitively on the edge set, and $2$ -arc-transitive transitively set of -arcs. In this paper, we present a classification for those graphs that are have soluble edge-stabilizers.

Let G be a finite group, and let 1G 6∈ S ⊆ G. A Cayley di-graph Γ = Cay(G,S) of G relative to S is a di-graph with a vertex set G such that, for x, y ∈ G, the pair (x, y) is an arc if and only if yx−1 ∈ S. Further, if S = S−1 := {s−1|s ∈ S}, then Γ is undirected. Γ is conected if and only if G = 〈s〉. A Cayley (di)graph Γ = Cay(G,S) is called normal if the right regular representation of G is a ...

This paper forms part of a study of 2-arc transitivity for finite imprimitive symmetric graphs, namely for graphs admitting an automorphism groupG that is transitive on ordered pairs of adjacent vertices, and leaves invariant a nontrivial vertex partition B. Such a group G is also transitive on the ordered pairs of adjacent vertices of the quotient graph B corresponding toB. If in additionG is ...

Half-arc-transitive graphs are a fascinating topic which connects graph theory, Riemann surfaces and group theory. Although fruitful results have been obtained over the last half century, it is still challenging to construct half-arc-transitive with prescribed vertex stabilizers. Until recently, there only six known connected tetravalent nonabelian stabilizers, question whether exists stabilize...

First and foremost, I have extensive experience with permutation group theory. There is an extensive literature on groups that act primitively on a set Ω, i.e., those groups which do not preserve a nontrivial system of blocks. Furthering this is the notion of quasiprimitivity. A group G acts quasiprimitively on a set Ω if every nontrivial normal subgroup of G is transitive on Ω. Every group act...

By definition, Cayley graphs are vertex-transitive, and graphs underlying regular or orientably-regular maps (on surfaces) are arc-transitive. This paper addresses questions about how large the automorphism groups of such graphs can be. In particular, it is shown how to construct 3-valent Cayley graphs that are 5-arc-transitive (in answer to a question by Cai Heng Li), and Cayley graphs of vale...