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Related papers: Counting cliques in $1$-planar graphs

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We estimate the maximum possible number of cliques of size $r$ in an $n$-vertex graph free of a fixed complete $r$-partite graph $K_{s_1, s_2, \ldots, s_r}$. By viewing every $r$-clique as a hyperedge, the upper bound on the Tur\'an number…

Combinatorics · Mathematics 2025-03-25 József Balogh , Suyun Jiang , Haoran Luo

A clique in an undirected graph G= (V, E) is a subset V' V of vertices, each pair of which is connected by an edge in E. The clique problem is an optimization problem of finding a clique of maximum size in graph. The clique problem is…

Discrete Mathematics · Computer Science 2007-10-04 Murali Krishna P , Sabu . M Thampi

Let $\Gamma(n,k)$ be the set of $2$-connected $n$-vertex graphs containing an edge that is not on any cycle of length at least $k+1.$ Let $g_s(n,k)$ denote the maximum number of $s$-cliques in a graph in $\Gamma(n,k).$ Recently, Ji and Ye…

Combinatorics · Mathematics 2023-09-13 Leilei Zhang

In recent years, there has been a surge of interest in extremal problems concerning the enumeration of independent sets or cliques in graphs with specific constraints. For instance, the Kahn-Zhao theorem establishes an upper bound on the…

Combinatorics · Mathematics 2026-01-06 Shi-Cai Gong , Jia-Jin Wang , Xin-Hao Zhu , Bo-Jun Yuan

We determine the maximum number of edges that a planar graph can have as a function of its maximum degree and matching number.

Combinatorics · Mathematics 2022-07-08 Lars Jaffke , Paloma T. Lima

In this work, we give the sharp upper bound for the number of cliques in graphs with bounded odd circumferences. This generalized Tur\'an-type result is an extension of the celebrated Erd\H{o}s and Gallai theorem and a strengthening of…

Combinatorics · Mathematics 2022-12-07 Zequn Lv , Ervin Győri , Zhen He , Nika Salia , Chuanqi Xiao , Xiutao Zhu

A grounded 1-bend string graph is an intersection graph of a set of polygonal lines, each with one bend, such that the lines lie above a common horizontal line $\ell$ and have exactly one endpoint on $\ell$. We show that the problem of…

Computational Geometry · Computer Science 2021-07-13 J. Mark Keil , Debajyoti Mondal , Ehsan Moradi , Yakov Nekrich

In this article we present the idea of clique ceiling numbers of the vertices of a given graph that has a universal vertex. We follow up with a polynomial-time algorithm to compute an upper bound for the clique number of such a graph using…

Combinatorics · Mathematics 2019-06-04 R. Dharmarajan , D. Ramachandran

We consider the maximum chromatic number of hypergraphs consisting of cliques that have pairwise small intersections. Designs of the appropriate parameters produce optimal constructions, but these are known to exist only when the number of…

Combinatorics · Mathematics 2023-04-12 Dhruv Mubayi , Jacques Verstraete

We address the problem of enumerating all maximal clique-partitions of an undirected graph and present an algorithm based on the observation that every maximal clique-partition can be produced from the maximal clique-cover of the graph by…

Discrete Mathematics · Computer Science 2023-09-26 Mircea Marin , Temur Kutsia , Cleo Pau , Mikheil Rukhaia

We study graphs whose chromatic number is close to the order of the graph (the number of vertices). Both when the chromatic number is a constant multiple of the order and when the difference of the chromatic number and the order is a small…

Combinatorics · Mathematics 2011-07-14 Csaba Biró

Extremal problems concerning the number of complete subgraphs have a long story in extremal graph theory. Let $k_s(G)$ be the number of $s$-cliques in a graph $G$ and $m={{r_m}\choose s}+t_m$, where $0\le t_m\leq r_m$. Edr\H{o}s showed that…

Spectral Theory · Mathematics 2020-03-17 Longfei Fang , Mingqing Zhai , Bing Wang

This paper is about: (1) bounds on the number of cliques in a graph in a particular class, and (2) algorithms for listing all cliques in a graph. We present a simple algorithm that lists all cliques in an $n$-vertex graph in O(n) time per…

Combinatorics · Mathematics 2012-02-09 Ken-ichi Kawarabayashi , David R. Wood

For a $k$-graph $\mathcal{F}\subset \binom{[n]}{k}$, the clique number of $\mathcal{F}$ is defined to be the maximum size of a subset $Q$ of $[n]$ with $\binom{Q}{k}\subset \mathcal{F}$. In the present paper, we determine the maximum number…

Combinatorics · Mathematics 2021-01-01 Peter Frankl , Erica L. L. Liu , Jian Wang

In this paper, we relate the problem of finding a maximum clique to the intersection number of the input graph (i.e. the minimum number of cliques needed to edge cover the graph). In particular, we consider the maximum clique problem for…

Discrete Mathematics · Computer Science 2012-04-19 S. Nikoletseas , C. Raptopoulos , P. G. Spirakis

Let k_r(n,m) denote the minimum number of r-cliques in graphs with n vertices and m edges. For r=3,4 we give a lower bound on k_r(n,m) that approximates k_r(n,m) with an error smaller than n^r/(n^2-2m). The solution is based on a constraint…

Combinatorics · Mathematics 2008-02-19 Vladimir Nikiforov

Finding complete subgraphs in a graph, that is, cliques, is a key problem and has many real-world applications, e.g., finding communities in social networks, clustering gene expression data, modeling ecological niches in food webs, and…

Optimization and Control · Mathematics 2017-05-01 Melisew Tefera Belachew , Nicolas Gillis

Clique-width is a well-studied graph parameter. For graphs of bounded clique-width, many problems that are NP-hard in general can be polynomial-time solvable. The fact motivates several studies to investigate whether the clique-width of…

Data Structures and Algorithms · Computer Science 2022-02-01 Yu Nakahata

Finding a maximum clique in a given graph is one of the fundamental NP-hard problems. We compare two multi-core thread-parallel adaptations of a state-of-the-art branch and bound algorithm for the maximum clique problem, and provide a novel…

Distributed, Parallel, and Cluster Computing · Computer Science 2014-09-05 Ciaran McCreesh , Patrick Prosser

This paper investigates some relationship between the algebraic connectivity and the clique number of graphs. We characterize all extremal graphs which have the maximum and minimum the algebraic connectivity among all graphs of order $n$…

Combinatorics · Mathematics 2013-07-02 Ya-Lei Jin , Xiao-Dong Zhang