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For a graph $G$ define the parameters $\ell(G)$ and $L(G)$ as the minimum and maximum value of $\nu(G\backslash F)$, where $F$ is a maximum matching of $G$ and $\nu(G)$ is the matching number of $G$. In this paper, we show that there is a…

Combinatorics · Mathematics 2025-04-29 Vahan Mkrtchyan

In this paper, we present a new simple degree-based estimator for the size of maximum matching in bounded arboricity graphs. When the arboricity of the graph is bounded by $\alpha$, the estimator gives a $\alpha+2$ factor approximation of…

Data Structures and Algorithms · Computer Science 2020-11-26 Hossein Jowhari

Let $G$ be a simple graph. The $k$-th neighborhood of a vertex subset $S \subseteq V(G)$, denoted $\Lambda^k(S)$, is the set of vertices that are adjacent to at least $k$ vertices in $S$. The $k$-th binding number $\beta^k(G)$ is defined as…

Combinatorics · Mathematics 2025-08-27 Guantao Chen , Mikhail Lavrov , Yuying Ma , Jennifer Vandenbussche , Hein van der Holst

For a graph $G$, let $\nu_s(G)$ be the induced matching number of $G$. We prove that $\nu_s(G) \geq \frac{n(G)}{(\lceil\frac{\Delta}{2}\rceil+1) (\lfloor\frac{\Delta}{2}\rfloor+1)}$ for every graph of sufficiently large maximum degree…

Combinatorics · Mathematics 2014-06-11 Felix Joos

The Bandwidth Theorem of B\"ottcher, Schacht and Taraz [Mathematische Annalen 343 (1), 175-205] gives minimum degree conditions for the containment of spanning graphs H with small bandwidth and bounded maximum degree. We generalise this…

Combinatorics · Mathematics 2013-05-10 Julia Böttcher , Anusch Taraz , Andreas Würfl

The inducibility of a graph $H$ measures the maximum number of induced copies of $H$ a large graph $G$ can have. Generalizing this notion, we study how many induced subgraphs of fixed order $k$ and size $\ell$ a large graph $G$ on $n$…

Combinatorics · Mathematics 2019-11-05 Noga Alon , Dan Hefetz , Michael Krivelevich , Mykhaylo Tyomkyn

A matching of a graph is a set of edges without common end vertex. A graph is called 1-planar if it admits a drawing in the plane such that each edge is crossed at most once. Recently, Biedl and Wittnebel proved that every 1-planar graph…

Combinatorics · Mathematics 2022-07-11 Yuanqiu Huang , Zhangdong Ouyang , Fengming Dong

For every graph $H$, there exists a polynomial-time algorithm deciding if a planar input graph $G$ can be contracted to~$H$. However, the degree of the polynomial depends on the size of $H$. In this paper, we identify a class of graphs…

Combinatorics · Mathematics 2010-12-14 Marcin Kaminski , Daniel Paulusma , Dimitrios M. Thilikos

We consider the problem of estimating the weight of a maximum weighted matching of a weighted graph $G(V,E)$ whose edges are revealed in a streaming fashion. We develop a reduction from the maximum weighted matching problem to the maximum…

Data Structures and Algorithms · Computer Science 2016-09-06 Elena Grigorescu , Morteza Monemizadeh , Samson Zhou

The degree diameter problem asks for the maximum possible number of vertices in a graph of maximum degree $\Delta$ and diameter $D$. In this paper, we focus on planar graphs of diameter $3$. Fellows, Hell and Seyffarth (1995) proved that…

Combinatorics · Mathematics 2025-07-28 Antoine Dailly , Sasha Darmon , Ugo Giocanti , Claire Hilaire , Petru Valicov

A major line of research is discovering Ramsey-type theorems, which are results of the following form: given a graph parameter $\rho$, every graph $G$ with sufficiently large $\rho(G)$ contains a `well-structured' induced subgraph $H$ with…

Combinatorics · Mathematics 2018-08-15 Ilkyoo Choi , Michitaka Furuya , Ringi Kim , Boram Park

A graph $G$ is $[a,b]$-covered if for each edge $e$ of $G$ there is an $[a,b]$-factor containing it. For $a=b=1$, an $[a,b]$-covered graph is a matching covered graph. The structural theory of matching covered graphs constitutes a…

Combinatorics · Mathematics 2026-05-07 Qixuan Yuan , Ruifang Liu , Jinjiang Yuan

It is well-known that every $n$-vertex planar graph with minimum degree 3 has a matching of size at least $\frac{n}{3}$. But all proofs of this use the Tutte-Berge-formula for the size of a maximum matching. Hence these proofs are not…

Data Structures and Algorithms · Computer Science 2019-02-22 Therese Biedl

It is well-known that every maximal planar graph has a matching of size at least $\tfrac{n+8}{3}$ if $n\geq 14$. In this paper, we investigate similar matching-bounds for maximal \emph{1-planar} graphs, i.e., graphs that can be drawn such…

Combinatorics · Mathematics 2023-01-05 Therese Biedl , John Wittnebel

An instance of the Connected Maximum Cut problem consists of an undirected graph G = (V, E) and the goal is to find a subset of vertices S $\subseteq$ V that maximizes the number of edges in the cut \delta(S) such that the induced graph…

Data Structures and Algorithms · Computer Science 2015-07-03 MohammadTaghi Hajiaghayi , Guy Kortsarz , Robert MacDavid , Manish Purohit , Kanthi Sarpatwar

For a connected graph $G$, let $\mu(G)$ denote the distance spectral radius of $G$. A matching in a graph $G$ is a set of disjoint edges of $G$. The maximum size of a matching in $G$ is called the matching number of $G$, denoted by…

Combinatorics · Mathematics 2025-12-04 Zengzhao Xu , Weige Xi , Ligong Wang

A subset of vertices of a graph is minimal if, within all subsets of the same size, its vertex boundary is minimal. We give a complete, geometric characterization of minimal sets for the planar integer lattice X. Our characterization…

Combinatorics · Mathematics 2020-09-28 Radhika Gupta , Ivan Levcovitz , Alexander Margolis , Emily Stark

The fourth listed author and Hans Parshall (\cite{IosevichParshall}) proved that if $E \subset {\mathbb F}_q^d$, $d \ge 2$, and $G$ is a connected graph on $k+1$ vertices such that the largest degree of any vertex is $m$, then if $|E| \ge C…

Combinatorics · Mathematics 2023-08-21 Paige Bright , Xinyu Fang , Barrett Heritage , Alex Iosevich , Maxwell Sun

Let $G$ be a graph with vertex set $V(G)$ and edge set $E(G)$. For $\alpha\in[0,1)$, we use $A_{\alpha}(G)$ and $\rho_{\alpha}(G)$ to denote the $A_{\alpha}$-matrix and the $A_{\alpha}$-spectral radius of $G$, respectively. The binding…

Combinatorics · Mathematics 2026-04-28 Sizhong Zhou , Hongxia Liu

We investigate the extremal properties of saturated partial plane embeddings of maximal planar graphs. For a planar graph $G$, the plane-saturation number $\mathrm{sat}_{\mathcal{P}}(G)$ denotes the minimum number of edges in a plane…

Combinatorics · Mathematics 2025-02-11 János Barát , Zoltán L. Blázsik , Balázs Keszegh , Zeyu Zheng
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