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A hypergraph is 2-intersecting if any two edges intersect in at least two vertices. Blais, Weinstein and Yoshida asked (as a first step to a more general problem) whether every 2-intersecting hypergraph has a vertex coloring with a constant…

Combinatorics · Mathematics 2020-06-12 Lucas Colucci , András Gyárfás

The $k$-core of a graph is the largest subgraph of minimum degree at least $k$. We show that for $k$ sufficiently large, the $(k + 2)$-core of a random graph $\G(n,p)$ asymptotically almost surely has a spanning $k$-regular subgraph. Thus…

Combinatorics · Mathematics 2007-06-11 Pawel Pralat , Jacques Verstraete , Nicholas Wormald

A graph is $2$-planar if it has local crossing number two, that is, it can be drawn in the plane such that every edge has at most two crossings. A graph is maximal $2$-planar if no edge can be added such that the resulting graph remains…

Combinatorics · Mathematics 2023-03-16 Michael Hoffmann , Meghana M. Reddy

An r-cut of a k-uniform hypergraph H is a partition of the vertex set of H into r parts and the size of the cut is the number of edges which have a vertex in each part. A classical result of Edwards says that every m-edge graph has a 2-cut…

Combinatorics · Mathematics 2019-07-01 David Conlon , Jacob Fox , Matthew Kwan , Benny Sudakov

Determining the maximum number of edges in an intersecting hypergraph on a fixed ground set under additional constraints is one of the central topics in extremal combinatorics. In contrast, there are few results on analogous problems…

Combinatorics · Mathematics 2025-04-08 Stijn Cambie , Jaehoon Kim , Hyunwoo Lee , Hong Liu , Tuan Tran

The main result of this paper is that for any $c>0$ and for large enough $n$ if the number of edges in a 3-uniform hypergraph is at least $cn^2$ then there is a core (subgraph with minimum degree at least 2) on at most 15 vertices. We…

Combinatorics · Mathematics 2016-06-21 David Solymosi , Jozsef Solymosi

We consider the maximum chromatic number of hypergraphs consisting of cliques that have pairwise small intersections. Designs of the appropriate parameters produce optimal constructions, but these are known to exist only when the number of…

Combinatorics · Mathematics 2023-04-12 Dhruv Mubayi , Jacques Verstraete

This article discusses random hypergraphs with varying hyperedge sizes, admitting large hyperedges with size tending to infinity, and heavy-tailed limiting hyperedge size distributions. The main result describes a threshold for the random…

Combinatorics · Mathematics 2024-06-11 Elmer Bergman , Lasse Leskelä

We prove tight bounds on the site percolation threshold for $k$-uniform hypergraphs of maximum degree $\Delta$ and for $k$-uniform hypergraphs of maximum degree $\Delta$ in which any pair of edges overlaps in at most $r$ vertices. The…

Probability · Mathematics 2023-09-25 Tyler Helmuth , Will Perkins , Michail Sarantis

In this paper we study conditions which guarantee the existence of perfect matchings and perfect fractional matchings in uniform hypergraphs. We reduce this problem to an old conjecture by Erd\H{o}s on estimating the maximum number of edges…

Combinatorics · Mathematics 2012-02-01 Noga Alon , Peter Frankl , Hao Huang , Vojtech Rodl , Andrzej Rucinski , Benny Sudakov

We study a variant of the Erd\H{o}s Matching Problem in random hypergraphs. Let $\mathcal{K}_p(n,k)$ denote the Erd\H{o}s-R\'enyi random $k$-uniform hypergraph on $n$ vertices where each possible edge is included with probability $p$. We…

Combinatorics · Mathematics 2025-09-24 Peter Frankl , Jiaxi Nie , Jian Wang

We study random subcube intersection graphs, that is, graphs obtained by selecting a random collection of subcubes of a fixed hypercube $Q_d$ to serve as the vertices of the graph, and setting an edge between a pair of subcubes if their…

Probability · Mathematics 2015-06-04 Victor Falgas-Ravry , Klas Markström

In this paper, we determine the minimum degree threshold of perfect matchings with high discrepancy in $r$-edge-colored $k$-uniform hypergraphs for all $k\geq 3$ and $r\geq 2$, thereby completing the investigation into discrepancies of…

Combinatorics · Mathematics 2024-09-10 Hongliang Lu , Jie Ma , Shengjie Xie

Inspired by earlier results about proper and polychromatic coloring of hypergraphs, we investigate such colorings of directed hypergraphs, that is, hypergraphs in which the vertices of each hyperedge is partitioned into two parts, a tail…

Combinatorics · Mathematics 2022-05-24 Balázs Keszegh

Let $H_{n,(p_m)_{m=2,\ldots,M}}$ be a random non-uniform hypergraph of dimension $M$ on $2n$ vertices, where the vertices are split into two disjoint sets of size $n$, and colored by two distinct colors. Each non-monochromatic edge of size…

Combinatorics · Mathematics 2015-11-18 Debarghya Ghoshdastidar , Ambedkar Dukkipati

We introduce a random hypergraph model for core-periphery structure. By leveraging our model's sufficient statistics, we develop a novel statistical inference algorithm that is able to scale to large hypergraphs with runtime that is…

Social and Information Networks · Computer Science 2022-06-03 Marios Papachristou , Jon Kleinberg

In this paper we focus on the problem of finding (small) subhypergraphs in a (large) hypergraph. We use this problem to illustrate that reducing hypergraph problems to graph problems by working with the 2-section is not always a reasonable…

A weighting of the edges of a hypergraph is called vertex-coloring if the weighted degrees of the vertices yield a proper coloring of the graph, i.e., every edge contains at least two vertices with different weighted degrees. In this paper…

Combinatorics · Mathematics 2016-05-20 Maciej Kalkowski , Michał Karoński , Florian Pfender

In this paper we study threshold coloring of graphs, where the vertex colors represented by integers are used to describe any spanning subgraph of the given graph as follows. Pairs of vertices with near colors imply the edge between them is…

Discrete Mathematics · Computer Science 2013-05-20 Md. Jawaherul Alam , Steven Chaplick , Gašper Fijavž , Michael Kaufmann , Stephen G. Kobourov , Sergey Pupyrev

In a simple, undirected graph G, an edge 2-coloring is a coloring of the edges such that no vertex is incident to edges with more than 2 distinct colors. The problem maximum edge 2-coloring (ME2C) is to find an edge 2-coloring in a graph G…

Discrete Mathematics · Computer Science 2025-05-07 Tobias Mömke , Alexandru Popa , Aida Roshany-Tabrizi , Michael Ruderer , Roland Vincze
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