Arc-transitive graphs of valency 8 have a semiregular automorphism∗
نویسنده
چکیده
One version of the polycirculant conjecture states that every vertex-transitive graph has a non-identity semiregular automorphism that is, a non-identity automorphism whose cycles all have the same length. We give a proof of the conjecture in the arc-transitive case for graphs of valency 8, which was the smallest open valency.
منابع مشابه
Semiregular automorphisms of edge-transitive graphs
The polycirculant conjecture asserts that every vertex-transitive digraph has a semiregular automorphism, that is, a nontrivial automorphism whose cycles all have the same length. In this paper we investigate the existence of semiregular automorphisms of edge-transitive graphs. In particular, we show that any regular edge-transitive graph of valency three or four has a semiregular automorphism.
متن کاملHalf-arc-transitive graphs of order 4p of valency twice a prime
A graph is half-arc-transitive if its automorphism group acts transitively on vertices and edges, but not on arcs. Let p be a prime. Cheng and Oxley [On weakly symmetric graphs of order twice a prime, J. Combin. Theory B 42(1987) 196-211] proved that there is no half-arc-transitive graph of order 2p, and Alspach and Xu [ 12 -transitive graphs of order 3p, J. Algebraic Combin. 3(1994) 347-355] c...
متن کاملA new family of locally 5-arc transitive graphs
We present a new family of locally 5–arc transitive graphs. The graphs constructed are bipartite with valency {2m + 1, 2m}. The actions of the automorphism group on the two bipartite halves are distinctly different and the corresponding amalgams are new.
متن کاملA classification of tightly attached half-arc-transitive graphs of valency 4
A graph is said to be half-arc-transitive if its automorphism group acts transitively on the set of its vertices and edges but not on the set of its arcs. With each half-arc-transitive graph of valency 4 a collection of the so called alternating cycles is associated, all of which have the same even length. Half of this length is called the radius of the graph in question. Moreover, any two adja...
متن کاملConstructing even radius tightly attached half-arc-transitive graphs of valency four
A finite graph X is half-arc-transitive if its automorphism group is transitive on vertices and edges, but not on arcs. When X is tetravalent, the automorphism group induces an orientation on the edges and a cycle of X is called an alternating cycle if its consecutive edges in the cycle have opposite orientations. All alternating cycles of X have the same length and half of this length is calle...
متن کامل