English
Related papers

Related papers: On certain edge-transitive bicirculants of twice o…

200 papers

A graph with $v$ vertices is $(r)$-pancyclic if it contains precisely $r$ cycles of every length from 3 to $v$. A bipartite graph with even number of vertices $v$ is said to be $(r)$-bipancyclic if it contains precisely $r$ cycles of each…

Combinatorics · Mathematics 2015-10-13 Abdollah Khodkar , Oliver Sawin , Lisa Mueller , WonHyuk Choi

A connected graph whose automorphism group acts transitively on the edges and vertices, but not on the set of ordered pairs of adjacent vertices of the graph is called half-arc-transitive. It is well known that the valence of a…

Combinatorics · Mathematics 2015-03-16 Primož Potočnik , Rok Požar

In this paper we investigate orders, longest cycles and the number of cycles of automorphisms of finite vertex-transitive graphs. In particular, we show that the order of every automorphism of a connected vertex-transitive graph with $n$…

Combinatorics · Mathematics 2021-06-15 Primoz Potocnik , Micael Toledo , Gabriel Verret

Nut graphs are graphs whose adjacency matrix is singular with one-dimensional null space spanned by a vector with no zero entries. In a recent paper, Ba\v{s}i\'c, Fowler and Pisanski proved that the automorphism group of a nut graph has…

Combinatorics · Mathematics 2025-08-26 Ksenija Rozman , Primož Šparl

The edges surrounding a face of a map $M$ form a cycle $C$, called the boundary cycle of the face, and $C$ is often not a simple cycle. If the map $M$ is arc-transitive, then there is a cyclic subgroup of automorphisms of $M$ which leaves…

Combinatorics · Mathematics 2021-11-05 Jiyong Chen , Cai Heng Li , Cheryl E. Praeger , Shu-Jiao Song

We call an oriented odd cycle alternating if it has exactly one vertex whose in-degree and out-degree are both positive. In this paper, we investigate whether certain graphs admit an orientation that avoids alternating odd cycles as…

Combinatorics · Mathematics 2025-08-27 Nóra Almási , Gábor Simonyi

A graph is called {\em half-arc-transitive} if its full automorphism group acts transitively on vertices and edges, but not on arcs. It is well known that for any prime $p$ there is no tetravalent half-arc-transitive graph of order $p$ or…

Combinatorics · Mathematics 2016-05-27 Yi Wang , Yan-Quan Feng

In this paper, we study 2-geodesic-transitive graphs of order twice an odd prime power. Classifications of corresponding basic graphs and such graphs with almost simple automorphism groups are given, and a reduction theorem for general case…

Combinatorics · Mathematics 2026-04-28 Jiangmin Pan , Cixuan Wu , Yingnan Zhang , Hanlin Zou

A graph is called a nut graph if zero is its eigenvalue of multiplicity one and its corresponding eigenvector has no zero entries. A graph is a bicirculant if it admits an automorphism with two equally sized vertex orbits. There are four…

Combinatorics · Mathematics 2025-02-11 Ivan Damnjanović , Nino Bašić , Tomaž Pisanski , Arjana Žitnik

A graph is said to be {\em 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…

Combinatorics · Mathematics 2007-05-23 Primoz Sparl

A circulant (di)graph is a (di)graph on n vertices that admits a cyclic automorphism of order n. This paper provides a survey of the work that has been done on finding the automorphism groups of circulant (di)graphs, including the…

Combinatorics · Mathematics 2007-05-23 Joy Morris

We classify trivalent vertex-transitive graphs whose edge sets have a partition into a 2-factor composed of two cycles and a 1-factor that is invariant under the action of the automorphism group.

Combinatorics · Mathematics 2021-09-15 Brian Alspach , Ted Dobson , Afsaneh Khodadadpour , Primoz Šparl

Following Alspach and Parsons, a {\em metacirculant graph} is a graph admitting a transitive group generated by two automorphisms $\rho$ and $\sigma$, where $\rho$ is $(m,n)$-semiregular for some integers $m \geq 1$, $n \geq 2$, and where…

Combinatorics · Mathematics 2007-05-23 Dragan Marusic , Primoz Sparl

In a graph $G$, a subset of vertices $S \subseteq V(G)$ is said to be cyclable if there is a cycle containing the vertices in some order. $G$ is said to be $k$-cyclable if any subset of $k \geq 2$ vertices is cyclable. If any $k$…

Combinatorics · Mathematics 2022-11-28 Niranjan Balachandran , Anish Hebbar

A set of vertices of a graph is distinguishing if the only automorphism that preserves it is the identity. The minimal size of such sets, if they exist, is the distinguishing cost. The distinguishing costs of vertex transitive cubic graphs…

Combinatorics · Mathematics 2025-07-09 Ted Dobson , Ademir Hujdurović , Wilfried Imrich , Ronald Ortner

One version of the polycirculant conjecture states that every vertex-transitive graph has a semiregular automorphism. We give a proof of the conjecture in the arc-transitive case for graphs of valency 8, which was the smallest open case.

Combinatorics · Mathematics 2013-03-20 Gabriel Verret

A graph is said to be $k$-{\em isoregular} if any two vertex subsets of cardinality at most $k$, that induce subgraphs of the same isomorphism type, have the same number of neighbors. It is shown that no $3$-isoregular bicirculant (and more…

Combinatorics · Mathematics 2025-01-31 Klavdija Kutnar , Dragan Marušič , Štefko Miklavič

In this paper we provide some sufficient conditions for the existence of an odd or even cycle that passing a given vertex or an edge in $2$-connected or $2$-edge connected graphs. We provide some similar conditions for the existence of an…

Discrete Mathematics · Computer Science 2015-12-09 Saieed Akbari , Khashayar Etemadi , Peyman Ezzati , Mehrdad Ghadiri

We investigate connected cubic vertex-transitive graphs whose edge sets admit a partition into a $2$-factor $\mathcal{C}$ and a $1$-factor that is invariant under a vertex-transitive subgroup of the automorphism group of the graph and where…

Combinatorics · Mathematics 2026-01-19 Brian Alspach , Primoz Sparl

A regular cover of a connected graph is called {\em cyclic} or {\em dihedral} if its transformation group is cyclic or dihedral respectively, and {\em arc-transitive} (or {\em symmetric}) if the fibre-preserving automorphism subgroup acts…

Combinatorics · Mathematics 2017-03-27 Da-Wei Yang , Yan-Quan Feng , Jin-Xin Zhou