English
Related papers

Related papers: On circulant nut graphs

200 papers

A vertex-girth-regular $vgr(v,k,g,\lambda)$-graph is a $k$-regular graph of girth $g$ and order $v$ in which every vertex belongs to exactly $\lambda$ cycles of length $g$. While all vertex-transitive graphs are necessarily…

Combinatorics · Mathematics 2024-08-28 Robert Jajcay , Jorik Jooken , István Porupsánszki

A graph $G = (V, E)$ is word-representable if there exists a word $w$ over the alphabet $V$ such that, for any two distinct vertices $x, y \in V$, $xy \in E$ if and only if $x$ and $y$ alternate in $w$. Two letters $x$ and $y$ are said to…

Combinatorics · Mathematics 2025-12-08 Suchanda Roy , Ramesh Hariharasubramanian

In the present paper we give an explicit formula which allows us immediately to describe a unique Gauss circuit on a framed 4-valent graph (a graph with a structure of opposite edges) from an arbitrary Euler tour on the graph whenever the…

Combinatorics · Mathematics 2009-12-01 Denis P. Ilyutko

The derived graph of a voltage graph consisting of a single vertex and two loops of different voltages is a circulant graph with two generators. We characterize the automorphism groups of connected, two-generator circulant graphs, and give…

Combinatorics · Mathematics 2024-08-08 Sally Cockburn , Sarah Loeb

In this paper we study the algebra of graph invariants, focusing mainly on the invariants of simple graphs. All other invariants, such as sorted eigenvalues, degree sequences and canonical permutations, belong to this algebra. In fact,…

Combinatorics · Mathematics 2008-01-30 Tomi Mikkonen , Xavier Buchwalder

In this paper, we aim to address the open questions raised in various recent papers regarding characterization of circulant graphs with three or four distinct eigenvalues in their spectra. Our focus is on providing characterizations and…

Combinatorics · Mathematics 2023-10-11 Milan Bašić

A hole is a chordless cycle with at least four vertices. A hole is odd if it has an odd number of vertices. A dart is a graph which vertices $a, b, c, d, e$ and edges $ab, bc, bd, be, cd, de$. Dart-free graphs have been actively studied in…

Combinatorics · Mathematics 2025-04-30 Chính T. Hoàng

A graph is said to be edge-transitive if its automorphism group acts transitively on its edges. It is known that edge-transitive graphs are either vertex-transitive or bipartite. In this paper we present a complete classification of all…

Combinatorics · Mathematics 2019-11-13 Heather A. Newman , Hector Miranda , Darren A. Narayan

Twin-width is a recently introduced graph parameter based on the repeated contraction of near-twins. It has shown remarkable utility in algorithmic and structural graph theory, as well as in finite model theory -- particularly since…

Combinatorics · Mathematics 2025-09-11 Irene Heinrich , Ferdinand Ihringer , Simon Raßmann , Lena Volk

A graph $G$ of constant link $L$ is a graph in which the neighborhood of any vertex induces a graph isomorphic to $L$. Given two different graphs, $H$ and $G$, the induced Tur\'an number ${\rm ex}(n; H, G{\rm -ind})$ is defined as the…

Combinatorics · Mathematics 2024-09-20 Yair Caro , Adriana Hansberg , Zsolt Tuza

A graph is said to be symmetric if its automorphism group is transitive on its arcs. Guo et al. (Electronic J. Combin. 18, \#P233, 2011) and Pan et al. (Electronic J. Combin. 20, \#P36, 2013) determined all pentavalent symmetric graphs of…

Combinatorics · Mathematics 2017-02-21 Bo Ling , Ben Gong Lou , Ci Xuan Wu

A circulant graph H is defined on the set of vertices V=\left\{ 1,\ldots,n\right\} and edges E=\left\{ \left(i,j\right):\left|i-j\right|\equiv s\left(\textrm{mod}n\right),s\in S\right\} , where S\subseteq\left\{…

Combinatorics · Mathematics 2017-07-17 Sebastian Richter , Israel Rocha

An internal partition of an $n$-vertex graph $G=(V,E)$ is a partition of $V$ such that every vertex has at least as many neighbors in its own part as in the other part. It has been conjectured that every $d$-regular graph with $n>N(d)$…

Combinatorics · Mathematics 2013-07-22 Amir Ban , Nati Linial

In this paper we investigate families of connected graphs which do not contain an odd cycle in their complement. Specifically, we consider graphs formed by two complete graphs connected in a particular way. We determine which of these…

Group Theory · Mathematics 2020-08-27 Jacob Laubacher , Mark Medwid

A connected graph of order $n$ admitting a semiregular automorphism of order $n/k$ is called a $k$-multicirculant. Highly symmetric multicirculants of small valency have been extensively studied, and several classification results exist for…

Combinatorics · Mathematics 2022-08-15 Primož Potočnik , Micael Toledo

We study graphs which admit an acyclic orientation that contains an out-branching and in-branching which are arc-disjoint (such an orientation is called {\bf good}). A {\bf 2T-graph} is a graph whose edge set can be decomposed into two…

Combinatorics · Mathematics 2019-12-11 Joergen Bang-Jensen , Matthias Kriesell

A total dominating set of a graph $G$ is a set $D$ of vertices of $G$ such that every vertex of $G$ has a neighbor in $D$. A locating-total dominating set of $G$ is a total dominating set $D$ of $G$ with the additional property that every…

Combinatorics · Mathematics 2016-07-25 Florent Foucaud , Michael A. Henning

We characterise the computational power of recurrent graph neural networks (GNNs) in terms of arithmetic circuits over the real numbers. Our networks are not restricted to aggregate-combine GNNs or other particular types. Generalising…

Computational Complexity · Computer Science 2026-05-05 Timon Barlag , Vivian Holzapfel , Laura Strieker , Jonni Virtema , Heribert Vollmer

Edge-girth-regular graphs (abbreviated as $egr$ graphs) are a class of highly regular graphs. More specifically, for integers $v$, $k$, $g$ and $\lambda$ an $egr(v,k,g,\lambda)$ graph is a $k$-regular graph with girth $g$ on $v$ vertices…

Combinatorics · Mathematics 2024-06-26 Jan Goedgebeur , Jorik Jooken

In this paper we study graphs which admit acyclic orientations that contain a pair of arc-disjoint out-branching and in-branching (such an orientation is called good) and we focus on edge-minimal such graphs. A 2T-graph is a graph whose…

Combinatorics · Mathematics 2019-03-26 J. Bang-Jensen , S. Bessy , J. Huang , M. Kriesell