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The independence complex of a graph G is a simplicial complex whose simplices are the independent sets in G. In the last couple of decades, the independence complexes of square grids (with various boundary conditions) have gained much…

Combinatorics · Mathematics 2022-06-07 Anurag Singh

In this article, we introduce the notion of a wedge of graphs and provide detailed computations for the independence complex of a wedge of path and cycle graphs. In particular, we show that these complexes are either contractible or wedges…

Combinatorics · Mathematics 2023-03-20 Navnath Daundkar , Saikat Panja , Sachchidanand Prasad

We show that the independence complexes of generalised Mycielskian of complete graphs are homotopy equivalent to a wedge sum of spheres, and determine the number of copies and the dimensions of these spheres. We also prove that the…

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

We study the independence complexes of families of well-covered circulant graphs discovered by Boros-Gurvich-Milani\v{c}, Brown-Hoshino, and Moussi. Because these graphs are well-covered, their independence complexes are pure simplicial…

Combinatorics · Mathematics 2015-05-13 Jonathan Earl , Kevin N. Vander Meulen , Adam Van Tuyl

The independence complex of a graph is a simplicial complex whose faces correspond to the independent sets of $G$. While independence complexes have been studied extensively for many graph classes, including square grid graphs, relatively…

Combinatorics · Mathematics 2025-12-25 Himanshu Chandrakar , Anurag Singh

For $r\geq 1$, the $r$-independence complex of a graph $G$ is a simplicial complex whose faces are subset $I \subseteq V(G)$ such that each component of the induced subgraph $G[I]$ has at most $r$ vertices. In this article, we determine the…

Algebraic Topology · Mathematics 2021-02-02 Priyavrat Deshpande , Anurag Singh

Given a simple undirected graph $G$ there is a simplicial complex $\mathrm{Ind}(G)$, called the independence complex, whose faces correspond to the independent sets of $G$. This is a well studied concept because it provides a fertile ground…

Combinatorics · Mathematics 2025-10-06 Fred M. Abdelmalek , Priyavrat Deshpande , Shuchita Goyal , Amit Roy , Anurag Singh

For every simple graph $G$, a class of multiple clique cluster-whiskered graphs $G^{md}$ is introduced, and it is shown that all graphs $G^{md}$ are vertex decomposable, thus the independence simplicial complex ${\rm Ind}\,G^{md}$ is…

Commutative Algebra · Mathematics 2018-06-14 A-Ming Liu , Tongsuo Wu

This paper investigates the shellability of $r$-independence complexes $\mathcal{I}_r(G)$, a generalization of classical independence complexes introduced by Paolini and Salvetti. For a graph $G$, a subset $A \subseteq V(G)$ is…

Combinatorics · Mathematics 2025-09-24 Arka Ghosh , S Selvaraja

We determine the homotopy types of the independence complexes of $(n \times 4)$ and $(n \times 5)$-square grid graphs. In fact, they are homotopy equivalent to wedges of spheres.

Algebraic Topology · Mathematics 2023-04-25 Takahiro Matsushita , Shun Wakatsuki

In this paper we define spherical complexes as simplicial complexes with the property that every subcomplex obtained by a sequence of links and deletions either has trivial homology, or has the homology of a sphere. Examples of such…

Commutative Algebra · Mathematics 2025-01-20 Sara Faridi , Thiago Holleben

We introduce the notion of \textit{star cluster} of a simplex in a simplicial complex. This concept provides a general tool to study the topology of independence complexes of graphs. We use star clusters to answer a question arisen from…

Combinatorics · Mathematics 2010-07-05 Jonathan Ariel Barmak

In this article, we define a family of regular bipartite graphs and show that the homotopy type of the independence complexes of this family is the wedge sum of spheres of certain dimensions.

Combinatorics · Mathematics 2017-09-15 Nandini Nilakantan , Samir Shukla

Independence complexes of circle graphs are purely combinatorial objects. However, when constructed from some diagram of a link $L$, they reveal topological properties of $L$, more specifically, of its Khovanov homology. We analyze the…

The independence complex $\mathrm{Ind}(G)$ of a graph $G$ is the simplicial complex formed by its independent sets. This article introduces a deformation of the simplicial boundary map of $\mathrm{Ind}(G)$ that gives rise to a double…

Algebraic Topology · Mathematics 2020-10-01 Marko Berghoff

We determine the homotopy types of the independence complexes of the $(n \times 6)$-square grid graphs. In fact, we show that these complexes are homotopy equivalent to wedges of spheres.

Algebraic Topology · Mathematics 2023-01-31 Takahiro Matsushita , Shun Wakatsuki

The enumeration of independent sets of regular graphs is of interest in statistical mechanics, as it corresponds to the solution of hard-particle models. In 2004, it was conjectured by Fendleyet al. that for some rectangular grids, with…

Combinatorics · Mathematics 2008-10-31 Mireille Bousquet-Mélou , Svante Linusson , Eran Nevo

Independent sets play a key role into the study of graphs and important problems arising in graph theory reduce to them. We define the monomial ideal of independent sets associated to a finite simple graph and describe its homological and…

Commutative Algebra · Mathematics 2013-07-12 Oana Olteanu

We show that the independence complex of a chordal graph is contractible if and only if this complex is dismantlable (strong collapsible) and it is homotopy equivalent to a sphere if and only if its core is a cross-polytopal sphere. The…

Combinatorics · Mathematics 2015-08-12 Michal Adamaszek

We show that if a graph $G$ involves a certain square grid graph as a full subgraph, then a certain operation on it yields a simplicial suspension of the independence complex of $G$. This generalizes a result of Csorba. As a corollary, we…

Algebraic Topology · Mathematics 2019-08-27 Kengo Okura
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