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Related papers: Large rainbow matchings in general graphs

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Given graphs $F$ and $H$, the generalized rainbow Tur\'an number $\text{ex}(n,F,\text{rainbow-}H)$ is the maximum number of copies of $F$ in an $n$-vertex graph with a proper edge-coloring that contains no rainbow copy of $H$. B. Janzer…

Combinatorics · Mathematics 2021-09-23 József Balogh , Michelle Delcourt , Emily Heath , Lina Li

For an edge-colored graph, a subgraph is called rainbow if all its edges have distinct colors. We show that if $G$ is an edge-colored graph of order $n$ and size $m$ using $c$ colors on its edges, and $m+c\geq \binom{n+1}{2}+k-1$ for a…

Combinatorics · Mathematics 2018-10-12 Stefan Ehard , Elena Mohr

A {\it rainbow matching} in an edge-colored graph is a matching in which all the edges have distinct colors. Wang asked if there is a function f(\delta) such that a properly edge-colored graph G with minimum degree \delta and order at least…

Combinatorics · Mathematics 2011-08-15 Jennifer Diemunsch , Michael Ferrara , Casey Moffatt , Florian Pfender , Paul S. Wenger

Let $G = (V, E)$ be an $n$-vertex edge-colored graph. In 2013, H. Li proved that if every vertex $v \in V$ is incident to at least $(n+1)/2$ distinctly colored edges, then $G$ admits a rainbow triangle. We prove that the same hypothesis…

Combinatorics · Mathematics 2021-02-24 Andrzej Czygrinow , Theodore Molla , Brendan Nagle , Roy Oursler

We prove that any $n$-vertex graph whose complement is triangle-free contains $n^2/12-o(n^2)$ edge-disjoint triangles. This is tight for the disjoint union of two cliques of order $n/2$. We also prove a corresponding stability theorem, that…

Combinatorics · Mathematics 2021-01-27 Mykhaylo Tyomkyn

Recently, Alon, Cambie, and Kang introduced asymmetric list coloring of bipartite graphs, where the size of each vertex's list depends on its part. For complete bipartite graphs, we fix the list sizes of one part and consider the resulting…

Combinatorics · Mathematics 2023-08-29 Daniel G. Zhu

A subgraph of an edge-coloured complete graph is called rainbow if all its edges have different colours. The study of rainbow decompositions has a long history, going back to the work of Euler on Latin squares. In this paper we discuss…

Combinatorics · Mathematics 2018-03-20 Alexey Pokrovskiy , Benny Sudakov

A rainbow matching in an edge-colored graph is a matching whose edges have distinct colors. We address the complexity issue of the following problem, \mrbm: Given an edge-colored graph $G$, how large is the largest rainbow matching in $G$?…

Discrete Mathematics · Computer Science 2013-12-30 Van Bang Le , Florian Pfender

Given a graph $G$ and a coloring of its edges, a subgraph of $G$ is called rainbow if its edges have distinct colors. The rainbow girth of an edge coloring of G is the minimum length of a rainbow cycle in G. A generalization of the famous…

Combinatorics · Mathematics 2024-09-25 Ron Aharoni , He Guo

A subgraph of an edge-coloured graph is called rainbow if all its edges have different colours. We prove a rainbow version of the blow-up lemma of Koml\'os, S\'ark\"ozy and Szemer\'edi that applies to almost optimally bounded colourings. A…

Combinatorics · Mathematics 2019-07-24 Stefan Ehard , Stefan Glock , Felix Joos

Let $K_{n,n}$ be the complete bipartite graph with $n$ vertices in each side. For each vertex draw uniformly at random a list of size $k$ from a base set $S$ of size $s=s(n)$. In this paper we estimate the asymptotic probability of the…

Combinatorics · Mathematics 2007-05-23 Michael Krivelevich , Asaf Nachmias

A subgraph of an edge-coloured complete graph is called rainbow if all its edges have different colours. In 1980 Hahn conjectured that every properly edge-coloured complete graph $K_n$ has a rainbow Hamiltonian path. Although this…

Combinatorics · Mathematics 2016-08-26 Noga Alon , Alexey Pokrovskiy , Benny Sudakov

We study a special case of the configuration model, in which almost all the vertices of the graph have degree $2$. We show that the graph has a very peculiar and interesting behaviour, in particular when the graph is made up by a vast…

Probability · Mathematics 2020-01-17 Lorenzo Federico

A $1-$factorization of a complete graph on $2n$ vertices is said to be $G-$regular if it posseses an automorphism group $G$ acting sharply transitively on the vertex-set. The problem of determining which groups can realize such a situation…

Combinatorics · Mathematics 2022-03-04 Gloria Rinaldi

A graph H is common if the number of monochromatic copies of H in a 2-edge-colouring of the complete graph is minimised by the random colouring. Burr and Rosta, extending a famous conjecture by Erdos, conjectured that every graph is common.…

Combinatorics · Mathematics 2022-04-28 Andrzej Grzesik , Joonkyung Lee , Bernard Lidický , Jan Volec

Given an edge-colored complete graph $K_n$ on $n$ vertices, a perfect (respectively, near-perfect) matching $M$ in $K_n$ with an even (respectively, odd) number of vertices is rainbow if all edges have distinct colors. In this paper, we…

Combinatorics · Mathematics 2020-12-14 Shuhei Saito , Wei Wu , Naoki Matsumoto

We solve four similar problems: For every fixed $s$ and large $n$, we describe all values of $n_1,\ldots,n_s$ such that for every $2$-edge-coloring of the complete $s$-partite graph $K_{n_1,\ldots,n_s}$ there exists a monochromatic (i)…

Combinatorics · Mathematics 2019-05-14 József Balogh , Alexandr Kostochka , Mikhail Lavrov , Xujun Liu

We prove that every $n$-vertex graph with at least $\binom{n}{2} - (n - 4)$ edges has a fractional triangle decomposition, for $n \ge 7$. This is a key ingredient in our proof, given in a companion paper, that every $n$-vertex $2$-coloured…

Combinatorics · Mathematics 2020-08-17 Vytautas Gruslys , Shoham Letzter

For the set of graphs with a given degree sequence, consisting of any number of $2's$ and $1's$, and its subset of bipartite graphs, we characterize the optimal graphs who maximize and minimize the number of $m$-matchings. We find the…

Combinatorics · Mathematics 2008-01-16 S. Friedland , E. Krop , K. Markström

We prove that every properly edge-colored $n$-vertex graph with average degree at least $100(\log n)^2$ contains a rainbow cycle, improving upon $(\log n)^{2+o(1)}$ bound due to Tomon. We also prove that every properly colored $n$-vertex…

Combinatorics · Mathematics 2022-11-08 Jaehoon Kim , Joonkyung Lee , Hong Liu , Tuan Tran