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We consider mining dense substructures (maximal cliques) from an uncertain graph, which is a probability distribution on a set of deterministic graphs. For parameter 0 < {\alpha} < 1, we present a precise definition of an {\alpha}-maximal…

Data Structures and Algorithms · Computer Science 2014-10-23 Arko Provo Mukherjee , Pan Xu , Srikanta Tirthapura

An old problem raised independently by Jacobson and Sch\"onheim asks to determine the maximum $s$ for which every graph with $m$ edges contains a pair of edge-disjoint isomorphic subgraphs with $s$ edges. In this paper we determine this…

Combinatorics · Mathematics 2012-10-16 Choongbum Lee , Po-Shen Loh , Benny Sudakov

Morris and Saxton used the method of containers to bound the number of $n$-vertex graphs with $m$ edges containing no $\ell$-cycles, and hence graphs of girth more than $\ell$. We consider a generalization to $r$-uniform hypergraphs. The…

Combinatorics · Mathematics 2021-10-19 Sam Spiro , Jacques Verstraëte

The induced subgraph of the corresponding Grassmann graph formed by simplex codes is considered. We show that this graph, as the Grassmann graph, contains two types of maximal cliques. For any two cliques of the first type there is a…

Combinatorics · Mathematics 2023-10-02 Mariusz Kwiatkowski , Mark Pankov

We show various upper bounds for the order of a digraph (or a mixed graph) whose Hermitian adjacency matrix has an eigenspace of prescribed codimension. In particular, this generalizes the so-called absolute bound for (simple) graphs first…

Combinatorics · Mathematics 2020-11-05 Alexander L. Gavrilyuk , Sho Suda

In this paper, we make progress on a question related to one of Galvin that has attracted substantial attention recently. The question is that of determining among all graphs $G$ with $n$ vertices and $\Delta(G)\leq r$, which has the most…

Combinatorics · Mathematics 2014-05-07 Jonathan Cutler , A. J. Radcliffe

An edge clique cover of a graph is a set of cliques that covers all edges of the graph. We generalize this concept to "$K_t$ clique cover", i.e. a set of cliques that covers all complete subgraphs on $t$ vertices of the graph, for every $t…

Combinatorics · Mathematics 2019-10-17 Hoang Dau , Olgica Milenkovic , Gregory J. Puleo

In 1995, Koml\'os, S\'ark\"ozy and Szemer\'edi showed that every large $n$-vertex graph with minimum degree at least $(1/2 + \gamma)n$ contains all spanning trees of bounded degree. We consider a generalization of this result to loose…

Combinatorics · Mathematics 2024-05-03 Yanitsa Pehova , Kalina Petrova

A graph is said to be well-covered if all its maximal independent sets are of the same size. In 1999, Yamashita and Kameda introduced a subclass of well-covered graphs, called localizable graphs and defined as graphs having a partition of…

Combinatorics · Mathematics 2017-01-09 Ademir Hujdurović , Martin Milanič , Bernard Ries

A graph with $n$ vertices is an $f(\cdot)$-dense graph if it has at least $f(n)$ edges, $f(\cdot)$ being a well-defined function. The notion $f(\cdot)$-dense graph encompasses various clique models like $\gamma$-quasi cliques, $k$-defective…

Data Structures and Algorithms · Computer Science 2025-11-07 Yi Zhou , Chunyu Luo , Zhengren Wang , Zhang-Hua Fu

In this paper we introduce a general framework for proving lower bounds for various Ramsey type problems within random settings. The main idea is to view the problem from an algorithmic perspective: we aim at providing an algorithm that…

Combinatorics · Mathematics 2014-08-25 Rajko Nenadov , Yury Person , Nemanja Škorić , Angelika Steger

In a random intersection graph $G_{n,m,p}$, each of $n$ vertices selects a random subset of a set of $m$ labels by including each label independently with probability $p$ and edges are drawn between vertices that have at least one label in…

Discrete Mathematics · Computer Science 2022-10-06 Filippos Christodoulou , Sotiris Nikoletseas , Christoforos Raptopoulos , Paul Spirakis

An open problem in graphical Gaussian models is to determine the smallest number of observations needed to guarantee the existence of the maximum likelihood estimator of the covariance matrix with probability one. In this paper we formalize…

Statistics Theory · Mathematics 2014-08-05 Emanuel Ben-David

We consider a variant of the clustering problem for a complete weighted graph. The aim is to partition the nodes into clusters maximizing the sum of the edge weights within the clusters. This problem is known as the clique partitioning…

Social and Information Networks · Computer Science 2023-09-15 Alexander Belyi , Stanislav Sobolevsky , Alexander Kurbatski , Carlo Ratti

We propose and study a hierarchical algorithm to generate graphs having a predetermined distribution of cliques, the fully connected subgraphs. The construction mechanism may be either random or incorporate preferential attachment. We…

Physics and Society · Physics 2009-11-13 Gregor Kaczor , Claudius Gros

Daligault, Rao and Thomass\'e asked whether a hereditary class of graphs well-quasi-ordered by the induced subgraph relation has bounded clique-width. Lozin, Razgon and Zamaraev recently showed that this is not true for classes defined by…

Combinatorics · Mathematics 2016-11-14 Konrad K. Dabrowski , Vadim V. Lozin , Daniël Paulusma

We consider the densest $k$-subgraph problem, which seeks to identify the $k$-node subgraph of a given input graph with maximum number of edges. This problem is well-known to be NP-hard, by reduction to the maximum clique problem. We…

Optimization and Control · Mathematics 2019-04-09 Polina Bombina , Brendan Ames

The importance of classifying connections in large graphs has been the motivation for a rich line of work on distributed subgraph finding that has led to exciting recent breakthroughs. A crucial aspect that remained open was whether…

Distributed, Parallel, and Cluster Computing · Computer Science 2022-09-27 Keren Censor-Hillel , Dean Leitersdorf , David Vulakh

Modern graph or network datasets often contain rich structure that goes beyond simple pairwise connections between nodes. This calls for complex representations that can capture, for instance, edges of different types as well as so-called…

Social and Information Networks · Computer Science 2020-02-19 Ilya Amburg , Nate Veldt , Austin R. Benson

In 2006, Collins and Trenk obtained a general sharp upper bound for the distinguishing chromatic number of a connected graph. Inspired by Catlin's combinatorial techniques from 1978, we establish improved upper bounds for classes of…

Combinatorics · Mathematics 2025-09-16 Amitayu Banerjee