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Related papers: Completing Partial Packings of Bipartite Graphs

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Given two graphs $G$ and $H$, we define $\textsf{v-cover}_{H}(G)$ (resp. $\textsf{e-cover}_{H}(G)$) as the minimum number of vertices (resp. edges) whose removal from $G$ produces a graph without any minor isomorphic to ${H}$. Also…

Data Structures and Algorithms · Computer Science 2017-01-23 Dimitris Chatzidimitriou , Jean-Florent Raymond , Ignasi Sau , Dimitrios M. Thilikos

Given two graphs $H$ and $F$, the maximum possible number of copies of $H$ in an $F$-free graph on $n$ vertices is denoted by $ex(n,H,F)$. We investigate the function $ex(n,H,kF)$, where $kF$ denotes $k$ vertex disjoint copies of a fixed…

Combinatorics · Mathematics 2018-06-05 Dániel Gerbner , Abhishek Methuku , Máté Vizer

For two graphs $F$ and $H$, the relative Tur\'{a}n number $\mathrm{ex}(H,F)$ is the maximum number of edges in an $F$-free subgraph of $H$. Foucaud, Krivelevich, and Perarnau \cite{FKP} and Perarnau and Reed \cite{PR} studied these…

Combinatorics · Mathematics 2021-06-18 Sam Spiro , Jacques Verstraëte

This paper studies edge-precoloring extensions in Cartesian products of graphs, motivated by a conjecture of Casselgren, Petros, and Fufa. We formulate a general hypothesis stating that if every edge-precoloring of $G$ and $H$ of sizes…

Combinatorics · Mathematics 2026-04-07 Pál Bärnkopf , Ervin Győri

The implicit representation conjecture concerns hereditary families of graphs. Given a graph in such a family, we want to assign some string of bits to each vertex in such a way that we can recover the information about whether 2 vertices…

Combinatorics · Mathematics 2018-12-14 Matthew Fitch

Recently, the problem of establishing bounds on the edge density of 1-planar graphs, including their subclass IC-planar graphs, has received considerable attention. In 2018, Angelini et al. showed that any n-vertex bipartite IC-planar graph…

Combinatorics · Mathematics 2025-06-03 Guiping Wang , Yuanqiu Huang , Zhangdong Ouyang , Licheng Zhang

Let $\phi_H^r(n)$ be the smallest integer such that, for all $r$-graphs $G$ on $n$ vertices, the edge set $E(G)$ can be partitioned into at most $\phi_H^r(n)$ parts, of which every part either is a single edge or forms an $r$-graph…

Combinatorics · Mathematics 2017-10-17 Xinmin Hou , Boyuan Liu , Hongliang Lu

Let $G$ be a graph and $\mathcal{H}$ be a hypergraph both on the same vertex set. We say that a hypergraph $\mathcal{H}$ is a \emph{Berge}-$G$ if there is a bijection $f : E(G) \rightarrow E(\mathcal{H})$ such that for $e \in E(G)$ we have…

Combinatorics · Mathematics 2015-06-01 Dániel Gerbner , Cory Palmer

In his study of graph codes, Alon introduced the concept of the odd-Ramsey number of a family of graphs $\mathcal{H}$ in $K_n$, defined as the minimum number of colours needed to colour the edges of $K_n$ so that every copy of a graph $H\in…

Combinatorics · Mathematics 2024-10-10 Simona Boyadzhiyska , Shagnik Das , Thomas Lesgourgues , Kalina Petrova

For a positive integer $k$, a graph property $\mathcal{H}$, and a graph parameter $\mathcal{P}$, let $\operatorname{ex}_{\mathcal{P}}(n, \mathcal{H}; \delta \geq k)$ denote the maximum value of $\mathcal{P}$ over all $n$-vertex graphs with…

Combinatorics · Mathematics 2026-04-02 Xu Liu , Bo Ning , Tao Wang

Let ${\cal{F}}=\{F_1,F_2,\ldots\}$ be a sequence of graphs such that $F_n$ is a graph on $n$ vertices with maximum degree at most $\Delta$. We show that there exists an absolute constant $C$ such that the vertices of any 2-edge-colored…

Combinatorics · Mathematics 2014-05-30 Andrey Grinshpun , Gabor N. Sarkozy

Given any graph $G$, the (adjacency) spread of $G$ is the maximum absolute difference between any two eigenvalues of the adjacency matrix of $G$. In this paper, we resolve a pair of 20-year-old conjectures of Gregory, Hershkowitz, and…

Combinatorics · Mathematics 2021-09-08 Jane Breen , Alex W. N. Riasanovsky , Michael Tait , John Urschel

We provide a deterministic polynomial-time algorithm that, for a given $k$-uniform hypergraph $H$ with $n$ vertices and edge density $d$, finds a complete $k$-partite subgraph of $H$ with parts of size at least ${c(d, k)(\log…

Combinatorics · Mathematics 2026-02-23 Ferran Espuña

For a $k$-uniform hypergraph $F$ let $\textrm{ex}(n,F)$ be the maximum number of edges of a $k$-uniform $n$-vertex hypergraph $H$ which contains no copy of $F$. Determining or estimating $\textrm{ex}(n,F)$ is a classical and central problem…

Combinatorics · Mathematics 2019-03-05 Christian Reiher , Vojtěch Rödl , Mathias Schacht

We consider an infinite version of the bipartite Tur\'{a}n problem. Let $G$ be an infinite graph with $V(G) = \mathbb{N}$ and let $G_n$ be the $n$-vertex subgraph of $G$ induced by the vertices $\{1,2, \dots, n \}$. We show that if $G$ is…

Combinatorics · Mathematics 2013-05-31 Xing Peng , Craig Timmons

We study the problem of partitioning the edges of a $d$-uniform hypergraph $H$ into a family $F$ of complete $d$-partite hypergraphs ($d$-cliques). We show that there is a partition $F$ in which every vertex $v \in V(H)$ belongs to at most…

For graphs $G$ and $H$, a homomorphism from $G$ to $H$, or $H$-coloring of $G$, is a map from the vertices of $G$ to the vertices of $H$ that preserves adjacency. When $H$ is composed of an edge with one looped endvertex, an $H$-coloring of…

Combinatorics · Mathematics 2016-10-21 John Engbers

We address a problem posed by Erd\H{o}s and Hajnal in 1991, proving that for all $n \geq 600$, every $(2n+1)$-vertex graph with at least $n^2 + n + 1$ edges contains two vertices of equal degree connected by a path of length three. The…

Combinatorics · Mathematics 2025-03-26 Kaizhe Chen , Jie Ma

In this paper, we provide an method to obtain the lower bound on the number of the distinct maximum genus embedding of the complete bipartite graph Kn;n (n be an odd number), which, in some sense, improves the results of S. Stahl and H.…

Combinatorics · Mathematics 2012-03-06 Guanghua Dong , Han Ren , Ning Wang , Yuanqiu Huang

The famous Sidorenko's conjecture asserts that for every bipartite graph $H$, the number of homomorphisms from $H$ to a graph $G$ with given edge density is minimized when $G$ is pseudorandom. We prove that for any graph $H$, a graph…

Combinatorics · Mathematics 2024-08-29 Seonghyuk Im , Ruonan Li , Hong Liu