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Related papers: A $B$-Restricted Clique Polynomial and Connections…

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Let $G$ be a finite simple graph and $B \subseteq V(G)$. We introduce the \emph{bivariate $B$-restricted clique polynomial} \[ C_B(G;x,y) = \sum_{\substack{K \subseteq V \\ K \text{ is a clique}}} x^{|K|} y^{|K \cap B|}, \] where the…

Combinatorics · Mathematics 2026-03-02 Hossein Teimoori Faal

Let $G$ be a graph and $t\ge 0$. A new graph parameter termed the largest reduced neighborhood clique cover number of $G$, denoted by ${\hat\beta}_t(G)$, is introduced. Specifically, ${\hat\beta}_t(G)$ is the largest, overall $t$-shallow…

Combinatorics · Mathematics 2018-02-13 Farhad Shahrokhi

A univariate graph polynomial P(G;X) is weakly distinguishing if for almost all finite graphs G there is a finite graph H with P(G;X)=P(H;X). We show that the clique polynomial and the independence polynomial are weakly distinguishing.…

Combinatorics · Mathematics 2023-06-22 Johann A. Makowsky , Vsevolod Rakita

For a tree decomposition $\mathcal{T}$ of a graph $G$, let $\mu(\mathcal{T})$ denote the maximum size of an induced matching in $G$ with the property that some bag of $\mathcal{T}$ contains at least one endpoint of every edge of the…

For a given graph $H$, its subdivisions carry the same topological structure. The existence of $H$-subdivisions within a graph $G$ has deep connections with topological, structural and extremal properties of $G$. One prominent example of…

Combinatorics · Mathematics 2023-08-22 Seonghyuk Im , Jaehoon Kim , Younjin Kim , Hong Liu

We say that a hereditary graph class $\mathcal{G}$ is \emph{clique-sparse} if there is a constant $k=k(\mathcal{G})$ such that for every graph $G\in\mathcal{G}$, every vertex of $G$ belongs to at most $k$ maximal cliques, and any maximal…

Combinatorics · Mathematics 2025-04-28 J. Pascal Gollin , Meike Hatzel , Sebastian Wiederrecht

In this work, we introduce the boundary polynomial of a graph $G$ as the ordinary generating function in two variables $B(G;x,y):= \displaystyle\sum_{S\subseteq V(G)} x^{|B(S)|}y^{|S|}$, where $B(S)$ denotes the outer boundary of $S$. We…

Combinatorics · Mathematics 2025-05-08 Walter Carballosa , Marcos Masip , Francisco A. Reyes

In 2020, we initiated a systematic study of graph classes in which the treewidth can only be large due to the presence of a large clique, which we call $(\mathrm{tw},\omega)$-bounded. While $(\mathrm{tw},\omega)$-bounded graph classes are…

Combinatorics · Mathematics 2023-10-18 Clément Dallard , Martin Milanič , Kenny Štorgel

Let $G$ be a graph and $t\ge 0$. The largest reduced neighborhood clique cover number of $G$, denoted by ${\hat\beta}_t(G)$, is the largest, overall $t$-shallow minors $H$ of $G$, of the smallest number of cliques that can cover any closed…

Combinatorics · Mathematics 2018-02-13 Farhad Shahrokhi

We provide a polynomial-time algorithm for b-Coloring on graphs of constant clique-width. This unifies and extends nearly all previously known polynomial time results on graph classes, and answers open questions posed by Campos and Silva…

Data Structures and Algorithms · Computer Science 2022-07-20 Lars Jaffke , Paloma T. Lima , Daniel Lokshtanov

We continue the study of $(\mathrm{tw},\omega)$-bounded graph classes, that is, hereditary graph classes in which the treewidth can only be large due to the presence of a large clique, with the goal of understanding the extent to which this…

Combinatorics · Mathematics 2023-12-19 Clément Dallard , Martin Milanič , Kenny Štorgel

Let H be a graph, and let C_H(G) be the number of (subgraph isomorphic) copies of H contained in a graph G. We investigate the fundamental problem of estimating C_H(G). Previous results cover only a few specific instances of this general…

Data Structures and Algorithms · Computer Science 2019-02-20 Martin Furer , Shiva Prasad Kasiviswanathan

Dallard, Milani\v{c}, and \v{S}torgel conjectured that for a hereditary graph class $\mathcal{G}$, if there is some function $f:\mathbb{N}\to\mathbb{N}$ such that every graph $G\in \mathcal{G}$ with clique number $\omega(G)$ has treewidth…

Combinatorics · Mathematics 2025-10-27 Sepehr Hajebi

Let $G$ be a simple graph of order $n$. The domination polynomial of $G$ is the polynomial $D(G, x)=\sum_{i=1}^n d(G,i) x^i$, where $d(G,i)$ is the number of dominating sets of $G$ of size $i$. For two graphs $G$ and $H$, let $\mathcal{C} =…

Combinatorics · Mathematics 2016-05-10 Somayeh Jahari , Saeid Alikhani

Given a digraph $G = (V_G, A_G)$, a \emph{branching} in $G$ is a set of arcs $B \subseteq A_G$ such that the underlying undirected graph spanned by $B$ is acyclic and each node in $G$ is entered (\emph{covered}) by at most one arc from $B$.…

Combinatorics · Mathematics 2007-05-23 Maxim A. Babenko , Pavel V. Nalivaiko

Clique-width is a well-studied graph parameter owing to its use in understanding algorithmic tractability: if the clique-width of a graph class ${\cal G}$ is bounded by a constant, a wide range of problems that are NP-complete in general…

Combinatorics · Mathematics 2021-12-23 Konrad K. Dabrowski , Matthew Johnson , Daniël Paulusma

Treewidth is an important graph invariant, relevant for both structural and algorithmic reasons. A necessary condition for a graph class to have bounded treewidth is the absence of large cliques. We study graph classes closed under taking…

Combinatorics · Mathematics 2021-11-09 Clément Dallard , Martin Milanič , Kenny Štorgel

Given two graphs $G$ and $H$, we say that $G$ contains $H$ as an induced minor if a graph isomorphic to $H$ can be obtained from $G$ by a sequence of vertex deletions and edge contractions. We study the complexity of Graph Isomorphism on…

Discrete Mathematics · Computer Science 2016-05-30 Rémy Belmonte , Yota Otachi , Pascal Schweitzer

Let $\alpha(G)$ and $\beta(G)$, denote the size of a largest independent set and the clique cover number of an undirected graph $G$. Let $H$ be an interval graph with $V(G)=V(H)$ and $E(G)\subseteq E(H)$, and let $\phi(G,H)$ denote the…

Combinatorics · Mathematics 2015-04-21 Farhad Shahrokhi

In this paper we introduce the concept of clique disjoint edge sets in graphs. Then, for a graph $G$, we define the invariant $\eta(G)$ as the maximum size of a clique disjoint edge set in $G$. We show that the regularity of the binomial…

Commutative Algebra · Mathematics 2020-07-21 M. Rouzbahani Malayeri , S. Saeedi Madani , D. Kiani
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