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A graph $G=(V,E)$ is total weight $(k,k')$-choosable if the following holds: For any list assignment $L$ which assigns to each vertex $v$ a set $L(v)$ of $k$ real numbers, and assigns to each edge $e$ a set $L(e)$ of $k'$ real numbers,…

Combinatorics · Mathematics 2022-02-22 Xuding Zhu

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

An antimagic labeling for a graph $G$ with $m$ edges is a bijection $f: E(G) \to \{1, 2, \dots, m\}$ so that $\phi_f(u) \neq \phi_f(v)$ holds for any pair of distinct vertices $u, v \in V(G)$, where $\phi_f(x) = \sum_{x \in e} f(e)$. A…

Combinatorics · Mathematics 2022-09-20 Daphne Der-Fen Liu , Vicente Lossada

Equitable list arboricity, introduced by Zhang in 2016, generalizes the notion of equitable list coloring by requiring the subgraph induced by each color class to be acyclic (instead of edgeless) in addition to the usual upper bound on the…

Combinatorics · Mathematics 2021-06-03 Hemanshu Kaul , Jeffrey A. Mudrock , Michael J. Pelsmajer

A graceful $l$-coloring of a graph $G$ is a proper vertex coloring with $l$ colors which induces a proper edge coloring with at most $l-1$ colors, where the color for an edge $ab$ is the absolute difference between the colors assigned to…

Combinatorics · Mathematics 2024-07-01 Laavanya D. , Devi Yamini S.

Let $G$ be a graph and let $f$ be a positive integer-valued function on $V(G)$ satisfying $2m\le f\le b$, where $b$ and $m$ are two positive integers with $b\ge 4m^2$. In this paper, we show that if $G$ is $b^2$-tough and $|V(G)|\ge b^2$,…

Combinatorics · Mathematics 2022-05-24 Morteza Hasanvand

A \emph{tree-partition} of a graph $G$ is a proper partition of its vertex set into `bags', such that identifying the vertices in each bag produces a forest. The \emph{tree-partition-width} of $G$ is the minimum number of vertices in a bag…

Combinatorics · Mathematics 2009-04-02 David R. Wood

A graph is distance magic if it admits a bijective labeling of its vertices by integers from $1$ up to the order of the graph in such a way that the sum of the labels of all the neighbors of a vertex is independent of a given vertex. We…

Combinatorics · Mathematics 2026-03-10 Petr Kovář , Ksenija Rozman , Primož Šparl

A (Euclidean) greedy drawing of a graph is a drawing in which, for any two vertices $s,t$ ($s \neq t$), there is a neighbor vertex of $s$ that is closer to $t$ than to $s$ in the Euclidean distance. Greedy drawings are important in the…

Combinatorics · Mathematics 2023-11-29 Hiroyuki Miyata , Reiya Nosaka

Graham and Sloane proposed in 1980 a conjecture stating that every tree has a harmonious labelling, a graph labelling closely related to additive base. Very limited results on this conjecture are known. In this paper, we proposed a…

Discrete Mathematics · Computer Science 2012-11-02 Wenjie Fang

When does a graph admit a tree-decomposition in which every bag has small diameter? For finite graphs, this is a property of interest in algorithmic graph theory, where it is called having bounded ``tree-length''. We will show that this is…

Combinatorics · Mathematics 2024-01-26 Eli Berger , Paul Seymour

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

An L(2, 1)-labeling of a graph is an assignment of nonnegative integers to the vertices of G such that adjacent vertices receive numbers differed by at least 2, and vertices at distance 2 are assigned distinct numbers. The L(2, 1)-labeling…

Combinatorics · Mathematics 2015-09-02 Dong Chen , Wai Chee Shiu , Qiaojun Shu , Pak Kiu Sun , Weifan Wang

The \emph{metric dimension} $\dim(G)$ of a graph $G$ is the minimum number of vertices such that every vertex of $G$ is uniquely determined by its vector of distances to the chosen vertices. The \emph{zero forcing number} $Z(G)$ of a graph…

Combinatorics · Mathematics 2017-06-20 Linda Eroh , Cong X. Kang , Eunjeong Yi

An equitable tree-$k$-coloring of a graph is a vertex $k$-coloring such that each color class induces a forest and the size of any two color classes differ by at most one. In this work, we show that every interval graph $G$ has an equitable…

Combinatorics · Mathematics 2020-03-10 Bei Niu , Bi Li , Xin Zhang

A proper total weighting of a graph $G$ is a mapping $\phi$ which assigns to each vertex and each edge of $G$ a real number as its weight so that for any edge $uv$ of $G$, $\sum_{e \in E(v)}\phi(e)+\phi(v) \ne \sum_{e \in…

Combinatorics · Mathematics 2017-05-24 Yu-Chang Liang , Tsai-Lien Wong , Xuding Zhu

Let $G = (V, E)$ be a finite simple undirected graph without $K_2$ components. A bijection $f : E \rightarrow \{1, 2,\cdots, |E|\}$ is called a local antimagic labeling if for any two adjacent vertices $u$ and $v$, they have different…

Combinatorics · Mathematics 2023-06-22 Martin Bača , Andrea Semaničová-Feňovčíková , Ruei-Ting Lai , Tao-Ming Wang

In 2012, Mader conjectured that for any tree $T$ of order $m$, every $k$-connected graph $G$ with minimum degree at least $\lfloor \frac{3k}{2}\rfloor+m-1$ contains a subtree $T'\cong T$ such that $G-V(T')$ remains $k$-connected. In 2022,…

Combinatorics · Mathematics 2025-11-11 Hojin Chu , Shinya Fujita , Boram Park , Homoon Ryu

For graphs F and G an F-matching in G is a subgraph of G consisting of pairwise vertex disjoint copies of F. The number of F-matchings in G is denoted by s(F,G). We show that for every fixed positive integer m and every fixed tree F, the…

Combinatorics · Mathematics 2010-06-29 Noga Alon , Simi Haber , Michael Krivelevich

In recent years, there has been significant interest in characterizing the induced subgraph obstructions to bounded treewidth and pathwidth. While this has recently been resolved for pathwidth, the case of treewidth remains open, and prior…

Combinatorics · Mathematics 2025-07-31 Maria Chudnovsky , David Fischer , Sepehr Hajebi , Sophie Spirkl , Bartosz Walczak
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