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We show that for every $d$-dimensional polytope, the hypergraph whose nodes are $k$-faces and whose hyperedges are $(k+1)$-faces of the polytope is strongly $(d-k)$-vertex connected, for each $0 \leq k \leq d- 1$.

Combinatorics · Mathematics 2021-07-21 Daniel Hathcock , Josephine Yu

We propose a new representation of $k$-partite, $k$-uniform hypergraphs, that is, a hypergraph with a partition of vertices into $k$ parts such that each hyperedge contains exactly one vertex of each type; we call them $k$-hypergraphs for…

Combinatorics · Mathematics 2025-02-19 Oksana Firman , Joachim Spoerhase

The {\em overlap number} of a finite $(d+1)$-uniform hypergraph $H$ is defined as the largest constant $c(H)\in (0,1]$ such that no matter how we map the vertices of $H$ into $\R^d$, there is a point covered by at least a $c(H)$-fraction of…

Combinatorics · Mathematics 2010-05-11 Jacob Fox , Mikhail Gromov , Vincent Lafforgue , Assaf Naor , Janos Pach

The convex dimension of a $k$-uniform hypergraph is the smallest dimension $d$ for which there is an injective mapping of its vertices into $\mathbb{R}^d$ such that the set of $k$-barycenters of all hyperedges is in convex position. We…

Combinatorics · Mathematics 2024-07-11 Leonardo Martínez-Sandoval , Arnau Padrol

A hypergraph generalizes the concept of an ordinary graph. In an ordinary graph, edges connect pairs of vertices, whereas in a hypergraph, hyperedges can connect multiple vertices at a time. In this paper, we obtain a relationship between…

Combinatorics · Mathematics 2023-09-19 Liya Jess Kurian , Chithra A

In this paper, we study the $d$-dimensional rectilinear drawings of the complete $d$-uniform hypergraph $K_{2d}^d$. Anshu et al. [Computational Geometry: Theory and Applications, 2017] used Gale transform and Ham-Sandwich theorem to prove…

Combinatorics · Mathematics 2019-10-29 Rahul Gangopadhyay , Saswata Shannigrahi

Given $k\ge3$ and $1\leq \ell< k$, an $(\ell,k)$-cycle is one in which consecutive edges, each of size $k$, overlap in exactly $\ell$ vertices. We study the smallest number of edges in $k$-uniform $n$-vertex hypergraphs which do not contain…

Combinatorics · Mathematics 2023-03-13 Andrzej Ruciński , Andrzej Żak

In this paper, we consider the embedding of a complete $d$-uniform geometric hypergraph with $n$ vertices in general position in $\mathbb{R}^d$, where each hyperedge is represented as a $(d-1)$-simplex, and a pair of hyperedges is defined…

Combinatorics · Mathematics 2016-02-02 Anurag Anshu , Saswata Shannigrahi

We introduce $k$-robust clique complexes, a family of simplicial complexes that generalizes the traditional clique complex. Here, a subset of vertices forms a simplex provided it does not contain an independent set of size $k$. We…

Combinatorics · Mathematics 2026-04-02 Marek Filakovský

This paper introduces a geometric representation of hypergraphs by representing hyperedges as simplices. Building on this framework, we employ homotopy groups to analyze the topological structure of hypergraphs embedded in high-dimensional…

Combinatorics · Mathematics 2025-11-14 Qiming Fang , Sihong Shao

The Gilbert graph $\text{Gilbert}(q,n,d)$, which arises naturally in graph theory and coding theory, is the regular graph on $\mathbb{F}_q^n$ in which two vertices are adjacent if their Hamming distance is less than $d$, and it is…

Combinatorics · Mathematics 2026-03-24 Noam Krupnik , Igal Sason , Abraham Berman

We introduce a graph structure on Euclidean polytopes. The vertices of this graph are the $d$-dimensional polytopes contained in $\mathbb{R}^d$ and its edges connect any two polytopes that can be obtained from one another by either…

Metric Geometry · Mathematics 2020-01-22 Julien David , Lionel Pournin , Rado Rakotonarivo

We consider high-order connectivity in $k$-uniform hypergraphs defined as follows: Two $j$-sets are $j$-connected if there is a walk of edges between them such that two consecutive edges intersect in at least $j$ vertices. We describe the…

Combinatorics · Mathematics 2017-04-20 Oliver Cooley , Mihyun Kang , Christoph Koch

Let $H=(V,E)$ be a hypergraph, where $V$ is a set of vertices and $E$ is a set of non-empty subsets of $V$ called edges. If all edges of $H$ have the same cardinality $r$, then $H$ is a $r$-uniform hypergraph; if $E$ consists of all…

Combinatorics · Mathematics 2018-08-03 Yingzhi Tian , Hong-Jian Lai , Jixiang Meng

We introduce a two-parameter framework that refines several classical graph invariants by imposing higher-order constraints along bounded-length geodesics. For integers $k,d\ge1$, a vertex set is called $k,d$-independent if every shortest…

Combinatorics · Mathematics 2026-01-09 Brent Cody , Rose Detore

We study hypergraph visualization via its topological simplification. We explore both vertex simplification and hyperedge simplification of hypergraphs using tools from topological data analysis. In particular, we transform a hypergraph to…

Human-Computer Interaction · Computer Science 2021-04-23 Youjia Zhou , Archit Rathore , Emilie Purvine , Bei Wang

We present a simple mechanism, which can be randomised, for constructing sparse $3$-uniform hypergraphs with strong expansion properties. These hypergraphs are constructed using Cayley graphs over $\mathbb{Z}_2^t$ and have vertex degree…

Combinatorics · Mathematics 2019-06-26 David Conlon

The paper studies the connectivity properties of facet graphs of simplicial complexes of combinatorial interest. In particular, it is shown that the facet graphs of $d$-cycles, $d$-hypertrees and $d$-hypercuts are, respectively, $(d+1)$,…

Combinatorics · Mathematics 2015-02-10 Ilan I. Newman , Yuri Rabinovich

It is known that polytopes with at most two nonsimple vertices are reconstructible from their graphs, and that $d$-polytopes with at most $d-2$ nonsimple vertices are reconstructible from their 2-skeletons. Here we close the gap between 2…

Combinatorics · Mathematics 2018-11-28 Guillermo Pineda-Villavicencio , Julien Ugon , David Yost

A cubical polytope is a polytope with all its facets being combinatorially equivalent to cubes. The paper is concerned with the linkedness of the graphs of cubical polytopes. A graph with at least $2k$ vertices is $k$-linked if, for every…

Combinatorics · Mathematics 2019-09-30 Hoa Thi Bui , Guillermo Pineda-Villavicencio , Julien Ugon
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