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Related papers: 2-dimensional vertex decomposable circulant graphs

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The prime-coprime graph $\Theta(G)$ of a finite group $G$ is the simple graph with vertex set $G$, where two distinct elements are adjacent whenever the greatest common divisor of their orders is either $1$ or a prime. We characterize all…

Group Theory · Mathematics 2026-04-21 Ravi Ranjan , Shubh Narayan Singh , Surbhi Kumari , Shidra Jamil

We study triangle decompositions of graphs. We consider constructions of classes of graphs where every edge lies on a triangle and the addition of the minimum number of multiple edges between already adjacent vertices results in a strongly…

Combinatorics · Mathematics 2021-08-23 C. M. Mynhardt , A. K. Wright

We investigate properties which ensure that a given finite graph is the commuting graph of a group or semigroup. We show that all graphs on at least two vertices such that no vertex is adjacent to all other vertices is the commuting graph…

Group Theory · Mathematics 2016-05-18 Michael Giudici , Bojan Kuzma

We give the first construction of explicit constant-degree lossless vertex expanders. Specifically, for any $\varepsilon > 0$ and sufficiently large $d$, we give an explicit construction of an infinite family of $d$-regular graphs where…

Combinatorics · Mathematics 2025-04-22 Jun-Ting Hsieh , Alexander Lubotzky , Sidhanth Mohanty , Assaf Reiner , Rachel Yun Zhang

In \cite{Chan95}, the authors classified the 2-extendable abelian Cayley graphs and posed the problem of characterizing all 2-extendable Cayley graphs. We first show that a connected bipartite Cayley (vertex-transitive) graph is…

Combinatorics · Mathematics 2016-12-12 Qiuli Li , Xing Gao

Call a simple graph $H$ of order $n$ well-separable, if by deleting a separator set of size $o(n)$ the leftover will have components of size at most $o(n)$. We prove, that bounded degree well-separable spanning subgraphs are easy to embed:…

Combinatorics · Mathematics 2007-07-18 Béla Csaba

Geometric modeling by constraints leads to large systems of algebraic equations. This paper studies bipartite graphs underlaid by systems of equations. It shows how these graphs make possible to polynomially decompose these systems into…

Discrete Mathematics · Computer Science 2014-05-26 Samy Ait-Aoudia , Roland Jegou , Dominique Michelucci

In earlier papers, we showed a decomposition of the arcs of 2-diregular digraphs (2-dds) and used it to prove some conditions for these graphs to be non-Hamiltonian; we then extended this decomposition to a larger class of digraphs and used…

Combinatorics · Mathematics 2026-01-27 Munagala V. Ramanath

A graph with at most two vertices of the same degree is called antiregular (Merris 2003), maximally nonregular (Zykov 1990) or quasiperfect (Behzad, Chartrand 1967). If s_{k} is the number of independent sets of cardinality k in a graph G,…

Discrete Mathematics · Computer Science 2010-07-07 Vadim E. Levit , Eugen Mandrescu

It has long been known that there exist finite connected tetravalent arc-transitive graphs with arbitrarily large vertex-stabilisers. However, beside a well known family of exceptional graphs, related to the lexicographic product of a cycle…

Combinatorics · Mathematics 2010-10-14 Primoz Potocnik , Pablo Spiga , Gabriel Verret

This study is the first part of a detailed study on Type-2 isomorphic circulant graphs having ten parts \cite{v2-1}-\cite{v2-10}. Circulant graphs $C_n(R)$ and $C_n(S)$ are said to be \emph{Adam's isomorphic} if there exist some $a\in…

Combinatorics · Mathematics 2026-05-13 Vilfred Kamalappan

A graph G is said to be 2-distinguishable if there is a 2-labeling of its vertices which is not preserved by any nontrivial automorphism of G. We show that every locally finite graph with infinite motion and growth at most…

Combinatorics · Mathematics 2013-01-09 Florian Lehner

A platypus graph is a non-hamiltonian graph for which every vertex-deleted subgraph is traceable. They are closely related to families of graphs satisfying interesting conditions regarding longest paths and longest cycles, for instance…

Combinatorics · Mathematics 2017-12-15 Jan Goedgebeur , Addie Neyt , Carol T. Zamfirescu

Motivated by longstanding conjectures regarding decompositions of graphs into paths and cycles, we prove the following optimal decomposition results for random graphs. Let $0<p<1$ be constant and let $G\sim G_{n,p}$. Let $odd(G)$ be the…

Combinatorics · Mathematics 2016-06-21 Stefan Glock , Daniela Kühn , Deryk Osthus

We study the set of numbers the total number of independent sets can admit in $n$-vertex graphs. In this paper, we prove that the cardinality $\mathcal{N}i(n)$ of this set is very close to $2^n$ in the following sense: $\mathcal{N}i(n)/2^n…

Combinatorics · Mathematics 2025-10-07 Benedek Kovács , Zoltán Lóránt Nagy

Graphlets are subgraphs rooted at a fixed vertex. The number of occurrences of graphlets aligned to a particular vertex, called graphlet degree sequence (gds), gives a topological description of the surrounding of the analyzed vertex.…

Combinatorics · Mathematics 2026-01-01 David Hartman , Aneta Pokorná , Daniel Trlifaj , Lluís Vena

Consider a group $\mathbb{G}$ and construct its power graph, whose vertex set consists of the elements of $\mathbb{G}$. Two distinct vertices (elements) are adjacent in the graph if and only if one element can be expressed as an integral…

Spectral Theory · Mathematics 2026-03-03 Priti Prasanna Mondal , Basit Auyoob Mir , Fouzul Atik

We study deterministic constructions of graphs for which the unique completion of low rank matrices is generically possible regardless of the values of the entries. We relate the completability to the presence of some patterns (particular…

Information Theory · Computer Science 2026-01-01 Augustin Cosse

We construct new resolvable decompositions of complete multigraphs and complete equipartite multigraphs into cycles of variable lengths (and a perfect matching if the vertex degrees are odd). We develop two techniques: {\em layering}, which…

Combinatorics · Mathematics 2018-09-26 Amin Bahmanian , Mateja Šajna

The simplex graph $S(G)$ of a graph $G$ is defined as the graph whose vertices are the cliques of $G$ (including the empty set), with two vertices being adjacent if, as cliques of $G$, they differ in exactly one vertex. Simplex graphs form…

Combinatorics · Mathematics 2025-03-24 Yan-Ting Xie , Shou-Jun Xu