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Related papers: Star clusters in independence complexes of graphs

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We show that the problem of identifying different signal components from a time-frequency representation can be equivalently phrased as a graph clustering problem: given a graph $G=(V,E)$ one aims to identify `clusters', subgraphs that are…

Signal Processing · Electrical Eng. & Systems 2025-10-10 Marcelo A. Colominas , Stefan Steinerberger , Hau-Tieng Wu

We present quantum complexity lower and upper bounds for independent set problems in graphs. In particular, we give quantum algorithms for computing a maximal and a maximum independent set in a graph. We present applications of these…

Quantum Physics · Physics 2007-05-23 Sebastian Doern

The independence number, coloring number and related parameters are investigated in the setting of oriented hypergraphs using the spectrum of the normalized Laplace operator. For the independence number, both an inertia--like bound and a…

Combinatorics · Mathematics 2021-09-24 Aida Abiad , Raffaella Mulas , Dong Zhang

We leverage an algorithm of Deming [R.W. Deming, Independence numbers of graphs -- an extension of the Koenig-Egervary theorem, Discrete Math., 27(1979), no. 1, 23--33; MR534950] to decompose a matchable graph into subgraphs with a precise…

Combinatorics · Mathematics 2022-05-24 P. Mark Kayll , Craig E. Larson

We review a range of stastistical methods for analyzing the structures of star clusters, and derive a new measure ${\cal Q}$ which both quantifies, and distinguishes between, a (relatively smooth) large-scale radial density gradient and…

Astrophysics · Physics 2009-11-10 Annabel Cartwright , Anthony P Whitworth

Homological index of a holomorphic 1-form on a complex analytic variety with an isolated singular point is an analogue of the usual index of a 1-form on a non-singular manifold. One can say that it corresponds to the top Chern number of a…

Algebraic Geometry · Mathematics 2018-07-03 Eugene Gorsky , Sabir M. Gusein-Zade

The combinatorial properties of double vertex graphs has been widely studied since the 90's. However only very few results are know about the independence number of such graphs. In this paper we obtain the independence numbers of the double…

Combinatorics · Mathematics 2024-11-12 Paloma Jiménez-Sepúlveda , Luis Manuel Rivera

By a finite type-graph we mean a graph whose set of vertices is the set of all $k$-subsets of $[n]=\{1,2,\ldots, n\}$ for some integers $n\ge k\ge 1$, and in which two such sets are adjacent if and only if they realise a certain order type…

Combinatorics · Mathematics 2017-09-12 Christian Avart , Bill Kay , Christian Reiher , Vojtěch Rödl

Symmetric edge polytopes are a recent and well-studied family of centrally symmetric polytopes arising from graphs. In this paper, we introduce a generalization of this family to arbitrary simplicial complexes. We show how topological…

Combinatorics · Mathematics 2026-02-20 Torben Donzelmann , Thiago Holleben , Martina Juhnke

The clique complex of a graph G is a simplicial complex whose simplices are all the cliques of G, and the line graph L(G) of G is a graph whose vertices are the edges of G and the edges of L(G) are incident edges of G. In this article, we…

Combinatorics · Mathematics 2022-04-29 Shuchita Goyal , Samir Shukla , Anurag Singh

In 2022 Kim showed when a graph $G$ is ternary (without induced cycles of length divisible by three), its independence complex $\text{Ind}(G)$ is either contractible or homotopy equivalent to a sphere. In this paper, we show that when…

Combinatorics · Mathematics 2025-09-29 Margaret Bayer , Richard Danner , Thiago Holleben , Marie Kramer , Yirong Yang

The behaviour and functioning of a variety of complex physical and biological systems depend on the spatial organisation of their constituent units, and on the presence and formation of clusters of functionally similar or related…

Physics and Society · Physics 2023-08-16 Silvia Rognone , Vincenzo Nicosia

For simple graphs $G$ and $H$, the Hom complex $\mathrm{Hom}(G,H)$ is a polyhedral complex whose vertices are the graph homomorphisms $G\to H$ and whose edges connect the pairs of homomorphisms which differ in a single vertex of $G$. Hom…

Combinatorics · Mathematics 2025-09-08 Soichiro Fujii , Yuni Iwamasa , Kei Kimura , Yuta Nozaki , Akira Suzuki

In this paper we introduce a path complex that can be regarded as a generalization of the notion of a simplicial complex. The main motivation for considering path complexes comes from directed graphs(digraphs). We obtain a new notion of the…

Combinatorics · Mathematics 2013-05-14 Alexander Grigor'yan , Yong Lin , Yuri Muranov , Shing-Tung Yau

It was proven by Gonz\'alez-Meneses, Manch\'on and Silvero that the extreme Khovanov homology of a link diagram is isomorphic to the reduced (co)homology of the independence simplicial complex obtained from a bipartite circle graph…

Geometric Topology · Mathematics 2016-08-11 Jozef H. Przytycki , Marithania Silvero

A vertex subset $W\subseteq V$ of the graph $G = (V,E)$ is an independent dominating set if every vertex in $V\setminus W$ is adjacent to at least one vertex in $W$ and the vertices of $W$ are pairwise non-adjacent. We enumerate independent…

General Mathematics · Mathematics 2019-10-14 Somayeh Jahari , Saeid Alikhani

Clustering nodes in heterophilous graphs is challenging as traditional methods assume that effective clustering is characterized by high intra-cluster and low inter-cluster connectivity. To address this, we introduce HeNCler-a novel…

Machine Learning · Computer Science 2025-06-25 Sonny Achten , Zander Op de Beeck , Francesco Tonin , Volkan Cevher , Johan A. K. Suykens

We propose a novel graph clustering method guided by additional information on the underlying structure of the clusters (or communities). The problem is formulated as the matching of a graph to a template with smaller dimension, hence…

Machine Learning · Statistics 2021-07-06 Mateus Riva , Florian Yger , Pietro Gori , Roberto M. Cesar , Isabelle Bloch

We show that all the tangles in a finite graph or matroid can be distinguished by a single tree-decomposition that is invariant under the automorphisms of the graph or matroid. This comes as a corollary of a similar decomposition theorem…

Combinatorics · Mathematics 2017-04-19 Reinhard Diestel , Fabian Hundertmark , Sahar Lemanczyk

Graph clustering is an unsupervised machine learning method that partitions the nodes in a graph into different groups. Despite achieving significant progress in exploiting both attributed and structured data information, graph clustering…

Machine Learning · Computer Science 2025-01-03 Rui Zhang , Xiaoyang Hou , Zhihua Tian , Yan he , Enchao Gong , Jian Liu , Qingbiao Wu , Kui Ren