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Related papers: A note on $k$-cordial $p$-uniform hypertrees

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Let $f:V\rightarrow\mathbb{Z}_k$ be a vertex labeling of a hypergraph $H=(V,E)$. This labeling induces an~edge labeling of $H$ defined by $f(e)=\sum_{v\in e}f(v)$, where the sum is taken modulo $k$. We say that $f$ is $k$-cordial if for all…

Combinatorics · Mathematics 2023-06-22 Michał Tuczyński , Przemysław Wenus , Krzysztof Węsek

For any integer $k>0$, a tree $T$ is $k$-cordial if there exists a labeling of the vertices of $T$ by $\mathbb{Z}_k$, inducing edge-weights as the sum modulo $k$ of the labels on incident vertices to a given edge, which furthermore…

Combinatorics · Mathematics 2019-10-03 Keith Driscoll

For any integer $k>0$, a tree $T$ is $k$-cordial if there exists a labeling of the vertices of $T$ by $\mathbb{Z}_k$, inducing a labeling on the edges with edge-weights found by summing the labels on vertices incident to a given edge modulo…

Combinatorics · Mathematics 2017-05-02 Keith Driscoll , Elliot Krop , Michelle Nguyen

For a graph $G$ and an abelian group $A$, a labeling of the vertices of $G$ induces a labeling of the edges via the sum of adjacent vertex labels. Hovey introduced the notion of an $A$-cordial vertex labeling when both the vertex and edge…

Hovey introduced $A$-cordial labelings as a generalization of cordial and harmonious labelings \cite{Hovey}. If $A$ is an Abelian group, then a labeling $f \colon V (G) \rightarrow A$ of the vertices of some graph $G$ induces an edge…

Combinatorics · Mathematics 2021-09-06 Sylwia Cichacz , Agnieszka Görlich , Zsolt Tuz

Hovey introduced $A$-cordial labelings as a generalization of cordial and harmonious labelings \cite{Hovey}. If $A$ is an Abelian group, then a labeling $f \colon V (G) \rightarrow A$ of the vertices of some graph $G$ induces an edge…

Combinatorics · Mathematics 2022-01-24 Sylwia Cichacz

A labeling of the vertices of a graph by elements of any abelian group $A$ induces a labeling of the edges by summing the labels of their endpoints. Hovey defined the graph $G$ to be $A$-cordial if it has such a labeling where the vertex…

Combinatorics · Mathematics 2022-03-25 Rebecca Patrias , Oliver Pechenik

Recently L. B. Beasley introduced $(2,3)$-cordial labelings of directed graphs in [1]. He made two conjectures which we resolve in this article. He conjectured that every orientation of a path of length at least five is $(2,3)$ cordial, and…

Combinatorics · Mathematics 2021-05-12 Manuel Santana , Jonathan Mousley , David Brown , Leroy Beasley

An $r$-uniform hypergraph $H$ consists of a set of vertices $V$ and a set of edges whose elements are $r$-subsets of $V$. We define a hypertree to be a connected hypergraph which contains no cycles. A hypertree spans a hypergraph $H$ if it…

Combinatorics · Mathematics 2020-10-12 Haya S. Aldosari , Catherine Greenhill

Let $\mathcal{H}$ be a $k$-uniform hypergraph. A chain in $\mathcal{H}$ is a sequence of its vertices such that every $k$ consecutive vertices form an edge. In 1999 Katona and Kierstead suggested to use chains in hypergraphs as the…

Combinatorics · Mathematics 2017-08-29 Gyula Y. Katona , Péter G. N. Szabó

Trees fill many extremal roles in graph theory, being minimally connected and serving a critical role in the definition of $n$-good graphs. In this article, we consider the generalization of trees to the setting of $r$-uniform hypergraphs…

Combinatorics · Mathematics 2017-10-17 Mark Budden , Andrew Penland

A classical result of Koml\'os, S\'ark\"ozy and Szemer\'edi shows that every large $n$-vertex graph with minimum degree at least $(1/2+\gamma)n$ contains all spanning trees of bounded degree. We generalised this result to loose spanning…

Combinatorics · Mathematics 2025-02-10 Yaobin Chen , Allan Lo

The $k$-expansion of a graph $G$ is the $k$-uniform hypergraph obtained from $G$ by adding $k-2$ new vertices to every edge. We determine, for all $k > d \geq 1$, asymptotically optimal $d$-degree conditions that ensure the existence of all…

Combinatorics · Mathematics 2025-07-14 Mengjiao Rao , Nicolás Sanhueza-Matamala , Lin Sun , Guanghui Wang , Wenling Zhou

A $(0,1)$-labeling of a set is said to be friendly if the number of elements of the set labeled 0 and the number labeled 1 differ by at most 1. Let $g$ be a labeling of the edge set of a graph that is induced by a labeling $f$ of the vertex…

Combinatorics · Mathematics 2022-12-13 LeRoy B. Beasley

A $k$-uniform hypergraph (or $k$-graph) $H = (V, E)$ is $k$-partite if $V$ can be partitioned into $k$ sets $V_1, \ldots, V_k$ such that each edge in $E$ contains precisely one vertex from each $V_i$. In this note, we consider list…

Combinatorics · Mathematics 2025-10-17 Abhishek Dhawan

A hypergraph $\mathcal{H}=(V,\mathcal{E})$ is a hypertree if it admits a tree $T$ with vertex set $V$ such that every edge of $\mathcal{H}$ induces a subtree of $T$. A tree like that is called a host tree. Several characterizations and…

Combinatorics · Mathematics 2025-04-25 Pablo De Caria Di Fonzo

We prove that for fixed $k$, every $k$-uniform hypergraph on $n$ vertices and of minimum codegree at least $n/2+o(n)$ contains every spanning tight $k$-tree of bounded vertex degree as a sub\-graph. This generalises a well-known result of…

Combinatorics · Mathematics 2023-06-12 Matías Pavez-Signé , Nicolás Sanhueza-Matamala , Maya Stein

It is known that the connected graphs that are $p$-good for all $p$ are the trees. In this paper, we ask which ordered trees are order-$p$-good for all $p$.

Combinatorics · Mathematics 2020-06-03 Jeremy F. Alm , Patrick Bahls , Kayla Coffey , Carolyn Langhoff

Chv\'atal showed that for any tree $T$ with $k$ edges the Ramsey number $R(T,n)=k(n-1)+1$ ("Tree-complete graph Ramsey numbers." Journal of Graph Theory 1.1 (1977): 93-93). For $r=3$ or $4$, we show that, if $T$ is an $r$-uniform…

Combinatorics · Mathematics 2024-12-30 Jiaxi Nie

A connected and acyclic hypergraph is called a supertree. In this paper we mainly focus on the spectral radii of uniform supertrees. Li, Shao and Qi determined the first two $k$-uniform supertrees with large spectral radii among all the…

Combinatorics · Mathematics 2015-02-24 Xiying Yuan
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