English
Related papers

Related papers: From flag complexes to banner complexes

200 papers

Intersection homology is defined for simplicial, singular and PL chains and it is well known that the three versions are isomorphic for a full filtered simplicial complex. In the literature, the isomorphism, between the singular and the…

Algebraic Topology · Mathematics 2025-10-15 David Chataur , Martin Saralegi-Aranguren , Daniel Tanré

Hypergraphs have seen widespread application in network and data science communities in recent years. We present a survey of recent work to construct auxiliary structures from hypergraphs -- specifically simplicial, relative, and chain…

Algebraic Topology · Mathematics 2025-10-14 Ellen Gasparovic , Emilie Purvine , Radmila Sazdanovic , Bei Wang , Yusu Wang , Lori Ziegelmeier

Via the BGG correspondence a simplicial complex Delta on [n] is transformed into a complex of coherent sheaves on P^n-1. We show that this complex reduces to a coherent sheaf F exactly when the Alexander dual Delta^* is Cohen-Macaulay. We…

Algebraic Geometry · Mathematics 2011-12-14 Gunnar Floystad , Jon Eivind Vatne

Hypergraphs, as a generalization of simplicial complexes, have long been a subject of interest in their geometric interpretation. The subdivision of simplicial complexes can, to some extent, provide insights into the geometry of simplicial…

Algebraic Topology · Mathematics 2023-11-17 Jian Liu , Ran Liu , Jie Wu

We construct and analyze an explicit basis for the homology of the boolean complex of a Coxeter system. This gives combinatorial meaning to the spheres in the wedge sum describing the homotopy type of the complex. We assign a set of…

Combinatorics · Mathematics 2011-04-01 Kari Ragnarsson , Bridget Eileen Tenner

I review the quantum kinematics of identical particles, which suggests new possibilities, beyond bosons and fermions, in 2+1 dimensions; and how simple flux-charge constructions embody the new possibilities, leading to both abelian and…

High Energy Physics - Theory · Physics 2015-05-13 Frank Wilczek

Let $W$ be a Weyl group corresponding to the root system $A_{n-1}$ or $B_n$. We define a simplicial complex $ \Delta^m_W $ in terms of polygon dissections for such a group and any positive integer $m$. For $ m=1 $, $ \Delta^m_W$ is…

Combinatorics · Mathematics 2007-05-23 Eleni Tzanaki

Let $G$ be a chordal graph and $I(G)$ its edge ideal. Let $\beta (I(G)) = (\beta_0, \beta_1, ..., \beta_p)$ denote the Betti sequence of $I(G)$, where $\beta_i$ stands for the $i$th total Betti number of $I(G)$ and where $p$ is the…

Combinatorics · Mathematics 2009-07-29 Takayuki Hibi , Kyouko Kimura , Satoshi Murai

Given a simplicial complex $\Delta$, we investigate how to construct a new simplicial complex $\bar{\Delta}$ such that the corresponding monomial ideals satisfy nice algebraic properties. We give a procedure to check the vertex…

Commutative Algebra · Mathematics 2023-04-25 Bijender , Ajay Kumar

We study $d$-dimensional simplicial complexes that are PL embeddable in $\mathbb{R}^{d+1}$. It is shown that such a complex must satisfy a certain homological condition. The existence of this obstruction allows us to provide a systematic…

Geometric Topology · Mathematics 2017-03-06 Anders Björner , Afshin Goodarzi

We consider a variety of connections between threshold graphs, shifted complexes, and simplicial complexes naturally formed from a graph. These graphical complexes include the independent set, neighborhood, and dominance complexes. We…

Combinatorics · Mathematics 2007-05-23 Caroline Klivans

Given a manifold with corners $X$, we associates to it the corner structure simplicial complex $\Sigma_X$. Its reduced K-homology is isomorphic to the K-theory of the $C^*$-algebra $\mathcal{K}_b(X)$ of b-compact operators on $X$. Moreover,…

K-Theory and Homology · Mathematics 2022-10-06 Thomas Schick , Mario Velasquez

This paper defines for each object $X$ that can be constructed out of a finite number of vertices and cells a vector $fX$ lying in a finite dimensional vector space. This is the flag vector of $X$. It is hoped that the quantum topological…

Combinatorics · Mathematics 2007-05-23 Jonathan Fine

In this paper, we give a new algebraic criterion for the {\em shellability} of (non-pure) simplicial complex $\Delta$ over $[n]$, shellable in the sense of Bj\"orner and Wachs \cite{BW}. We show that the spanning simplicial complex of…

Commutative Algebra · Mathematics 2017-04-20 Imran Anwar , Zunaira Kosar , Shaheen Nazir , Khurram Shabbir

A prism is the product space $\Delta \times I$ where $\Delta$ is a 2-simplex and $I$ is a closed interval. As an analogue of simplicial complexes, we introduce prism complexes and show that every compact $3$-manifold has a prism complex…

Geometric Topology · Mathematics 2023-05-23 Tejas Kalelkar , Ramya Nair

Suppose $G$ is a connected complex Lie group and $H$ is a closed complex subgroup such that $X := G/H$ is Kaehler and the codimension of the top non-vanishing homology group of $X$ with coefficients in $\mathbb Z_2$ is less than or equal to…

Complex Variables · Mathematics 2016-12-30 Seyed Ruhallah Ahmadi , Bruce Gilligan

For a simplicial complex X on {1,2, ..., n} we define enriched homology and cohomology modules. They are graded modules over k[x_1, ..., x_n] whose ranks are equal to the dimensions of the reduced homology and cohomology groups. We…

Combinatorics · Mathematics 2011-12-14 Gunnar Floystad

We compute the double complex of smooth complex-valued differential forms on projective bundles over and blow-ups of compact complex manifolds up to a suitable notion of quasi-isomorphism. This simultaneously yields formulas for 'all'…

Algebraic Geometry · Mathematics 2019-07-30 Jonas Stelzig

A numerical characterization is given of the so-called h-triangles of sequentially Cohen-Macaulay simplicial complexes. This result characterizes the number of faces of various dimensions and codimensions in such a complex, generalizing the…

Combinatorics · Mathematics 2017-03-06 Karim A. Adiprasito , Anders Björner , Afshin Goodarzi

We consider a multi-parameter model for randomly constructing simplicial complexes. This model interpolates between random clique complexes and Linial-Meshulam random $k$-dimensional complexes, two models that have been extensively studied.…

Algebraic Topology · Mathematics 2015-06-04 Christopher F. Fowler