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Related papers: Finding Connected Dense $k$-Subgraphs

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The $k$-deck of a graph is its multiset of induced subgraphs on $k$ vertices. We prove that $n$-vertex graphs with maximum degree $2$ have the same $k$-decks if each cycle has at least $k+1$ vertices, each path component has at least $k-1$…

Combinatorics · Mathematics 2016-09-02 Douglas B. West , Hannah Spinoza

As a generalization of the concept of a metric basis, this article introduces the notion of $k$-metric basis in graphs. Given a connected graph $G=(V,E)$, a set $S\subseteq V$ is said to be a $k$-metric generator for $G$ if the elements of…

Combinatorics · Mathematics 2015-02-05 Alejandro Estrada-Moreno , Juan A. Rodríguez-Velázquez , Ismael G. Yero

Motivated by applications in graph drawing and information visualization, we examine the planar split thickness of a graph, that is, the smallest $k$ such that the graph is $k$-splittable into a planar graph. A $k$-split operation…

For a simple graph G = (V, E) and a positive integer k greater than or equal to 2, a coloring of vertices of G using exactly k colors such that every vertex has an equal number of vertices of each color in its closed neighborhood is called…

Combinatorics · Mathematics 2025-10-21 Maurice Almeida , Ravindra Pawar , Siddharth Gupta , Tarkeshwar Singh

Finding dense subgraphs is a core problem in graph mining with many applications in diverse domains. At the same time many real-world networks vary over time, that is, the dataset can be represented as a sequence of graph snapshots. Hence,…

Data Structures and Algorithms · Computer Science 2023-08-31 Chamalee Wickrama Arachchi , Nikolaj Tatti

In distributed networks, it is often useful for the nodes to be aware of dense subgraphs, e.g., such a dense subgraph could reveal dense subtructures in otherwise sparse graphs (e.g. the World Wide Web or social networks); these might…

Distributed, Parallel, and Cluster Computing · Computer Science 2012-08-08 Atish Das Sarma , Ashwin Lall , Danupon Nanongkai , Amitabh Trehan

The problem of enumerating connected subgraphs of a given size in a graph has been extensively studied in recent years. In this paper, we propose an algorithm with a delay of $O(k\Delta)$ for enumerating all connected induced subgraphs of…

Data Structures and Algorithms · Computer Science 2025-07-09 Chenglong Xiao , Chengyong Mao , Shanshan Wang

We show how to find and efficiently maintain maximal k-edge-connected subgraphs in undirected graphs. In particular, we provide the following results. (1) A general framework for maintaining the maximal k-edge-connected subgraphs upon…

Data Structures and Algorithms · Computer Science 2023-05-02 Loukas Georgiadis , Giuseppe F. Italiano , Evangelos Kosinas , Debasish Pattanayak

Let $k\ge 2$ be fixed integer, $0<c<1$ a constant. Consider a graph $G$ with $n$ vertices and average degree $cn$. We answer a question of Simon Griffiths by showing that $G$ has $k$ vertices such that their neighborhoods together cover at…

Combinatorics · Mathematics 2026-05-01 Janos Pach

For an ordered set $W=\{w_1,w_2,...,w_k\}$ of vertices and a vertex $v$ in a connected graph $G$, the ordered $k$-vector $r(v|W):=(d(v,w_1),d(v,w_2),.,d(v,w_k))$ is called the (metric) representation of $v$ with respect to $W$, where…

Combinatorics · Mathematics 2011-03-21 Mohsen Jannesari , Behnaz Omoomi

In this note we prove that for every integer $k$, there exist constants $g_{1}(k)$ and $g_{2}(k)$ such that the following holds. If $G$ is a graph on $n$ vertices with maximum degree $\Delta$ then it contains an induced subgraph $H$ on at…

Combinatorics · Mathematics 2017-05-26 António Girão , Kamil Popielarz

A graph $G$ is called $k$-factor-critical if $G-S$ has a perfect matching for every $S\subseteq G$ with $|S|=k$. A connected graph $G$ is called $t$-connected if it has more than $t$ vertices and remains connected whenever fewer than $t$…

Combinatorics · Mathematics 2025-09-03 Tingyan Ma , Edwin R. van Dam , Ligong Wang

In this article the extremal structures for the mean order of connected induced subgraphs of cographs are determined. It is shown that among all connected cographs of order $n \ge 7$, the star $K_{1,n-1}$ has maximum mean connected induced…

Combinatorics · Mathematics 2017-08-08 Matthew E. Kroeker , Lucas Mol , Ortrud R. Oellermann

Let $G=(V,E)$ be an undirected graph without loops and multiple edges. A subset $C\subseteq V$ is called \emph{identifying} if for every vertex $x\in V$ the intersection of $C$ and the closed neighbourhood of $x$ is nonempty, and these…

Combinatorics · Mathematics 2009-02-04 Sylvain Gravier , Svante Janson , Tero Laihonen , Sanna Ranto

For a graph $G$, let $f(G)$ be the largest integer $k$ for which there exist two vertex-disjoint induced subgraphs of $G$ each on $k$ vertices, both inducing the same number of edges. We prove that $f(G) \ge n/2 - o(n)$ for every graph $G$…

Combinatorics · Mathematics 2016-09-07 Béla Bollobás , Teeradej Kittipassorn , Bhargav Narayanan , Alex Scott

Dense subgraph discovery is an important primitive in graph mining, which has a wide variety of applications in diverse domains. In the densest subgraph problem, given an undirected graph $G=(V,E)$ with an edge-weight vector $w=(w_e)_{e\in…

Social and Information Networks · Computer Science 2021-10-27 Atsushi Miyauchi , Akiko Takeda

For a constant $\gamma \in[0,1]$ and a graph $G$, let $\omega_{\gamma}(G)$ be the largest integer $k$ for which there exists a $k$-vertex subgraph of $G$ with at least $\gamma\binom{k}{2}$ edges. We show that if $0<p<\gamma<1$ then…

Combinatorics · Mathematics 2018-03-29 Paul Balister , Béla Bollobás , Julian Sahasrabudhe , Alexander Veremyev

The $k$-representation number of a graph $G$ is the minimum cardinality of the system of vertex subsets with the property that every edge of $G$ is covered at least $k$ times while every non-edge is covered at most $(k-1)$ times. In…

Combinatorics · Mathematics 2024-03-05 Ayush Basu , Vojtěch Rödl , Marcelo Sales

We consider the minimum vertex cover problem in hypergraphs in which every hyperedge has size k (also known as minimum hitting set problem, or minimum set cover with element frequency k). Simple algorithms exist that provide…

Data Structures and Algorithms · Computer Science 2010-12-14 Jean Cardinal , Marek Karpinski , Richard Schmied , Claus Viehmann

For integers $k \geq 2$ and $n \geq k+1$, we prove the following: If $n\cdot k$ is even, there is a connected $k$-regular graph on $n$ vertices. If $n\cdot k$ is odd, there is a connected nearly $k$-regular graph on $n$ vertices.

Combinatorics · Mathematics 2018-01-26 Ghurumuruhan Ganesan