Abstract A connected graph of order n admitting a semiregular automorphism / k is called -multicirculant. Highly symmetric multicirculants small valency have been extensively studied, and several classification results exist for cubic vertex- arc-transitive multicirculants. In this paper, we study the broader class vertex-transitive graphs an /3 or larger that may not be semiregular. particular...

Every finite, self-dual, regular (or chiral) 4-polytope of type {3, q, 3} has a trivalent 3-transitive (or 2-transitive) medial layer graph. Here, by dropping self-duality, we obtain a construction for semisymmetric trivalent graphs (which are edgebut not vertex-transitive). In particular, the Gray graph arises as the medial layer graph of a certain universal locally toroidal regular 4-polytope.

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.