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Related papers: A characterization on $(g,f)$-parity orientations

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For an undirected, simple, finite, connected graph $G$, we denote by $V(G)$ and $E(G)$ the sets of its vertices and edges, respectively. A function $\varphi:E(G)\rightarrow \{1,...,t\}$ is called a proper edge $t$-coloring of a graph $G$,…

Discrete Mathematics · Computer Science 2013-07-16 N. N. Davtyan

A $k$-uniform hypergraph $G=(V,E)$ is called odd-bipartite ([5]), if $k$ is even and there exists some proper subset $V_1$ of $V$ such that each edge of $G$ contains odd number of vertices in $V_1$. Odd-bipartite hypergraphs are…

Combinatorics · Mathematics 2014-03-20 Jia-Yu Shao , Hai-Ying Shan , Bao-feng Wu

For each positive integer $n$, the Fibonacci-sum graph $G_n$ on vertices $1,2,\ldots,n$ is defined by two vertices forming an edge if and only if they sum to a Fibonacci number. It is known that each $G_n$ is bipartite, and all Hamiltonian…

Combinatorics · Mathematics 2017-10-31 Andrii Arman , David S. Gunderson , Pak Ching Li

For a graph $G$ and $a,b\in V(G)$, the shortest path reconfiguration graph of $G$ with respect to $a$ and $b$ is denoted by $S(G,a,b)$. The vertex set of $S(G,a,b)$ is the set of all shortest paths between $a$ and $b$ in $G$. Two vertices…

Combinatorics · Mathematics 2017-05-29 John Asplund , Kossi Edoh , Ruth Haas , Yulia Hristova , Beth Novick , Brett Werner

For a graph $G = (V, E)$, the $\gamma$-graph of $G$ is the graph whose vertex set is the collection of minimum dominating sets, or $\gamma$-sets of $G$, and two $\gamma$-sets are adjacent if they differ by a single vertex and the two…

Combinatorics · Mathematics 2020-11-04 Christopher M. van Bommel

Graph representations are the generalization of geometric graph drawings from the plane to higher dimensions. A method introduced by Tutte to optimize properties of graph drawings is to minimize their energy. We explore this minimization…

Computational Geometry · Computer Science 2023-09-07 Matt DeVos , Danielle Rogers , Alexandra Wesolek

Let $G$ be a finite group. For a fixed element $g$ in $G$ and a given subgroup $H$ of $G$, the relative $g$-noncommuting graph of $G$ is a simple undirected graph whose vertex set is $G$ and two vertices $x$ and $y$ are adjacent if $x \in…

Group Theory · Mathematics 2020-08-11 Monalisha Sharma , Rajat Kanti Nath

Proportional choosability is a list coloring analogue of equitable coloring. Specifically, a $k$-assignment $L$ for a graph $G$ specifies a list $L(v)$ of $k$ available colors to each $v \in V(G)$. An $L$-coloring assigns a color to each…

Combinatorics · Mathematics 2020-06-04 Jeffrey A. Mudrock , Robert Piechota , Paul Shin , Tim Wagstrom

The Helmholtzian matrix of a graph $G=(V(G),E(G))$ is a graph-theoretic analogue of the vector Laplacian (or Helmholtz operator) [S. Li, L. Lu, J.F. Wang, A graph discretization of vector Laplacian, 379 (2026) 446--460]. Motivated by the…

Combinatorics · Mathematics 2026-05-06 Lu Lu , Yongtang Shi , Zoran Stanić , Jianfeng Wang , Yi Wang

We say that a digraph $D$ is $(i,j)$-step competitive if any two vertices have an $(i,j)$-step common out-neighbor in $D$ and that a graph $G$ is $(i,j)$-step competitively orientable if there exists an $(i,j)$-step competitive orientation…

Combinatorics · Mathematics 2024-10-08 Myungho Choi , Suh-Ryung Kim

Let $G$ and $H$ be two simple graphs. A bijection $\phi:V(G)\rightarrow V(H)$ is called an isomorphism between $G$ and $H$ if $(\phi v_i)(\phi v_j)\in E(H)$ $\Leftrightarrow$ $v_i v_j\in E(G)$, $\forall v_i,v_j \in V(G)$. In the case that…

Combinatorics · Mathematics 2017-10-27 Wenxue Du

A semi-proper orientation of a given graph $G$, denoted by $(D,w)$, is an orientation $D$ with a weight function $w: A(D)\rightarrow \mathbb{Z}_+$, such that the in-weight of any adjacent vertices are distinct, where the in-weight of $v$ in…

Combinatorics · Mathematics 2020-07-21 Ruijuan Gu , Gregory Gutin , Yongtang Shi , Zhenyu Taoqiu

Recently, Bauer et al. (J Graph Theory 55(4) (2007), 343--358) introduced a graph operator $D(G)$, called the $D$-graph of $G$, which has been useful in investigating the structural aspects of maximal Tutte sets in $G$ with a perfect…

Combinatorics · Mathematics 2009-09-30 Cheng Yeaw Ku , Kok Bin Wong

Let $\gamma(G)$ be the domination number of a graph $G$. A graph $G$ is \emph{domination-vertex-critical}, or \emph{$\gamma$-vertex-critical}, if $\gamma(G-v)< \gamma(G)$ for every vertex $v \in V(G)$. In this paper, we show that: Let $G$…

Combinatorics · Mathematics 2009-06-05 Tao Wang , Qinglin Yu

A graph $G(V,E)$ of order $|V|=p$ and size $|E|=q$ is called super edge-graceful if there is a bijection $f$ from $E$ to $\{0,\pm 1,\pm 2,...,\pm \frac{q-1}{2}\}$ when $q$ is odd and from $E$ to $\{\pm 1,\pm 2,...,\pm \frac{q}{2}\}$ when…

Combinatorics · Mathematics 2012-04-05 Sylwia Cichacz , Dalibor Froncek , Wenjie Xu

Graphs can have different properties that lead to several graph types and may allow for a varying representation of diverse information. In order to clarify the modeling power of graphs, we introduce a partial order on the most common graph…

Discrete Mathematics · Computer Science 2022-09-08 Josephine M. Thomas , Silvia Beddar-Wiesing , Alice Moallemy-Oureh , Rüdiger Nather

A graph $G$ of order $2n$ is called degree-equipartite if for every $n$-element set $A\subseteq V(G)$, the degree sequences of the induced subgraphs $G[A]$ and $G[V(G)\setminus A]$ are the same. In this paper, we characterize all…

Combinatorics · Mathematics 2011-08-09 Khodakhast Bibak , Mohammad Hassan Shirdareh Haghighi

A graph is said to be a Sterboul--Deming graph if $KE(G)=\emptyset$, that is, if every vertex of $G$ belongs to a posy or a flower (structures introduced by Sterboul, Deming, and Edmonds). These graphs can be regarded as the structural…

Combinatorics · Mathematics 2026-03-11 Kevin Pereyra

The power graph $\mathcal{P}(G)$ is the simple undirected graph with group elements as a vertex set and two elements are adjacent if one of them is a power of the other. The order supergraph $\mathcal{S}(G)$ of the power graph…

Combinatorics · Mathematics 2023-10-09 Manisha , Parveen , Jitender Kumar

To each finite frame $\varphi$ in an inner product space $\mathcal{H}$ we associate a simple graph $G(\varphi)$, called {\it frame graph}, with the vectors of the frame as vertices and there is an edge between vertices $f$ and $g$ provided…

Combinatorics · Mathematics 2022-01-06 H. Najafi , F. Abdollahi