English
Related papers

Related papers: Tolerance for colorful Tverberg partitions

200 papers

A proper edge colouring of a graph is adjacent vertex distinguishing if no two adjacent vertices see the same set of colours. Using a clever application of the Local Lemma, Hatami (2005) proved that every graph with maximum degree $\Delta$…

Combinatorics · Mathematics 2020-11-04 Gwenaël Joret , William Lochet

A coloring of a graph $G=(V,E)$ is a partition $\{V_1, V_2, \ldots, V_k\}$ of $V$ into independent sets or color classes. A vertex $v\in V_i$ is a Grundy vertex if it is adjacent to at least one vertex in each color class $V_j$ for every…

Combinatorics · Mathematics 2015-12-10 Zixing Tang , Baoyindureng Wu , Lin Hu , Manoucheher Zaker

A split graph is a graph whose vertex set can be partitioned into a clique and an independent set. A connected graph $G$ is said to be $t$-admissible if admits a spanning tree in which the distance between any two adjacent vertices of $G$…

Combinatorics · Mathematics 2024-11-05 Fernanda Couto , Diego Amaro Ferraz , Sulamita Klein

Birch and Tverberg partitions are closely related concepts from discrete geometry. We show two properties for the number of Birch partitions: Evenness, and a lower bound. This implies the first non-trivial lower bound for the number of…

Combinatorics · Mathematics 2008-04-17 Stephan Hell

We consider the problem of coloring a 3-colorable graph in polynomial time using as few colors as possible. This is one of the most challenging problems in graph algorithms. In this paper using Blum's notion of ``progress'', we develop a…

Data Structures and Algorithms · Computer Science 2024-06-04 Ken-ichi Kawarabayashi , Mikkel Thorup , Hirotaka Yoneda

In this paper, we study the embedding of a complete balanced $d$-partite $d$-uniform hypergraph with all its $nd$ vertices represented as points in general position in $\mathbb{R}^d$ and each hyperedge drawn as a convex hull of $d$…

Combinatorics · Mathematics 2020-12-17 Rahul Gangopadhyay , Saswata Shannigrahi

We prove that for every integer $t\geq 1$, the class of intersection graphs of curves in the plane each of which crosses a fixed curve in at least one and at most $t$ points is $\chi$-bounded. This is essentially the strongest…

Combinatorics · Mathematics 2017-10-05 Alexandre Rok , Bartosz Walczak

A coloring is distinguishing (or symmetry breaking) if no non-identity automorphism preserves it. The distinguishing threshold of a graph $G$, denoted by $\theta(G)$, is the minimum number of colors $k$ so that every $k$-coloring of $G$ is…

Combinatorics · Mathematics 2022-12-19 Saeid Alikhani , Mohammad Hadi Shekarriz

Our basic objects are partitions of finite sets of points into disjoint subsets. We investigate sets of partitions which are closed under taking tensor products, composition and involution, and which contain certain base partitions. These…

Combinatorics · Mathematics 2015-09-04 Pierre Tarrago , Moritz Weber

We study colorings of the hyperbolic plane, analogously to the Hadwiger-Nelson problem for the Euclidean plane. The idea is to color points using the minimum number of colors such that no two points at distance exactly $d$ are of the same…

Combinatorics · Mathematics 2017-01-31 Hugo Parlier , Camille Petit

We prove that for any point set P in the plane, a triangle T, and a positive integer k, there exists a coloring of P with k colors such that any homothetic copy of T containing at least ck^8 points of P, for some constant c, contains at…

Computational Geometry · Computer Science 2012-12-12 Jean Cardinal , Kolja Knauer , Piotr Micek , Torsten Ueckerdt

We examine maximum vertex coloring of random geometric graphs, in an arbitrary but fixed dimension, with a constant number of colors. Since this problem is neither scale-invariant nor smooth, the usual methodology to obtain limit laws…

Probability · Mathematics 2016-11-17 Sem Borst , Milan Bradonjić

We consider two graph colouring problems in which edges at distance at most $t$ are given distinct colours, for some fixed positive integer $t$. We obtain two upper bounds for the distance-$t$ chromatic index, the least number of colours…

Combinatorics · Mathematics 2015-10-29 Tomáš Kaiser , Ross J. Kang

In his recent work, Andrews revisited two-color partitions with certain restrictions on the differences between consecutive parts, and he established three theorems linking these two-color partitions with more familiar kinds of partitions.…

Combinatorics · Mathematics 2022-02-08 Shishuo Fu

We prove that for every integer $k$, every finite set of points in the plane can be $k$-colored so that every half-plane that contains at least $2k-1$ points, also contains at least one point from every color class. We also show that the…

Combinatorics · Mathematics 2015-05-19 Shakhar Smorodinsky , Yelena Yuditsky

Hadwiger and Haj\'{o}s conjectured that for every positive integer $t$, $K_{t+1}$-minor free graphs and $K_{t+1}$-topological minor free graphs are properly $t$-colorable, respectively. Clustered coloring version of these two conjectures…

Combinatorics · Mathematics 2022-12-06 Chun-Hung Liu

A well-studied coloring problem is to assign colors to the edges of a graph $G$ so that, for every pair of vertices, all edges of at least one shortest path between them receive different colors. The minimum number of colors necessary in…

Data Structures and Algorithms · Computer Science 2018-01-17 L. Sunil Chandran , Anita Das , Davis Issac , Erik Jan van Leeuwen

A matching in a graph is uniquely restricted if no other matching covers exactly the same set of vertices. This notion was defined by Golumbic, Hirst, and Lewenstein and studied in a number of articles. Our contribution is twofold. We…

Combinatorics · Mathematics 2016-11-22 Julien Baste , Dieter Rautenbach , Ignasi Sau

Let $S$ be a set of $n$ points in $\mathbb{R}^d$. A Steiner convex partition is a tiling of ${\rm conv}(S)$ with empty convex bodies. For every integer $d$, we show that $S$ admits a Steiner convex partition with at most $\lceil…

Computational Geometry · Computer Science 2014-02-04 Adrian Dumitrescu , Sariel Har-Peled , Csaba D. Tóth

We study a Tur\'an-type problem on edge-colored complete graphs. We show that for any $r$ and $t$, any sufficiently large $r$-edge-colored complete graph on $n$ vertices with $\Omega(n^{2-1/tr^r})$ edges in each color contains a member from…

Combinatorics · Mathematics 2021-07-16 Matt Bowen , Adriana Hansberg , Amanda Montejano , Alp Müyesser