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Related papers: Compact Widts in Metric Trees

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Motivated by the analysis and geometry of metric-measure structures in infinite dimensions, we study the category of extended metric-topological spaces, along with many of its distinguished subcategories (such as the one of compact spaces).…

Category Theory · Mathematics 2026-01-13 Enrico Pasqualetto , Timo Schultz , Janne Taipalus

We prove a general width duality theorem for combinatorial structures with well-defined notions of cohesion and separation. These might be graphs and matroids, but can be much more general or quite different. The theorem asserts a duality…

Combinatorics · Mathematics 2021-01-19 Reinhard Diestel , Sang-il Oum

In a metric space, such as the real numbers with their standard metric, a set A is open if and only if no sequence with terms outside of A has a limit inside A. Moreover, a metric space is compact if and only if every sequence has a…

General Topology · Mathematics 2010-06-24 Stijn Vermeeren

The collection $\mathcal{M}_n$ of all metric spaces on $n$ points whose diameter is at most $2$ can naturally be viewed as a compact convex subset of $\mathbb{R}^{\binom{n}{2}}$, known as the metric polytope. In this paper, we study the…

Probability · Mathematics 2022-05-31 Gady Kozma , Tom Meyerovitch , Ron Peled , Wojciech Samotij

We prove that for every graph $G$ with $n$ vertices, the treewidth of $G$ plus the treewidth of the complement of $G$ is at least $n-2$. This bound is tight.

Combinatorics · Mathematics 2013-06-18 Gwenaël Joret , David R. Wood

For every $n\in \mathbb{N}$, we present a set $S_n$ of $O(n^{3/2}\log n)$ points in the plane such that every planar 3-tree with $n$ vertices has a straight-line embedding in the plane in which the vertices are mapped to a subset of $S_n$.…

Computational Geometry · Computer Science 2013-10-02 Radoslav Fulek , Csaba D. Tóth

Chain distance between points in a metric space is defined as the infimum of epsilon such that there is an epsilon-chain connecting these points. We call a mapping of a metric compact into the real line a chain development if it preserves…

Metric Geometry · Mathematics 2016-04-05 Yu. V. Malykhin , E. V. Shchepin

Decompositional parameters such as treewidth are commonly used to obtain fixed-parameter algorithms for NP-hard graph problems. For problems that are W[1]-hard parameterized by treewidth, a natural alternative would be to use a suitable…

Data Structures and Algorithms · Computer Science 2022-03-01 Cornelius Brand , Esra Ceylan , Christian Hatschka , Robert Ganian , Viktoriia Korchemna

Hypergraph width measures are a class of hypergraph invariants important in studying the complexity of constraint satisfaction problems (CSPs). We present a general exact exponential algorithm for a large variety of these measures. A…

Computational Complexity · Computer Science 2011-06-24 Lukas Moll , Siamak Tazari , Marc Thurley

The connected tree-width of a graph is the minimum width of a tree-decomposition whose parts induce connected subgraphs. Long cycles are examples of graphs that have small tree-width but large connected tree-width. We show that a graph has…

Combinatorics · Mathematics 2015-10-15 Reinhard Diestel , Malte Müller

The metric dimension of a graph $G$ is defined as the minimum number of vertices in a subset $S\subset V(G)$ such that all other vertices are uniquely determined by their distances to the vertices in $S$, and is denoted by $\dim(G)$. In…

Combinatorics · Mathematics 2025-08-19 Rui Gao , Yingqing Xiao , Zhanqi Zhang

We present a constraint model for the problem of producing a tree decomposition of a graph. The inputs to the model are a simple graph G, the number of nodes in the desired tree decomposition and the maximum cardinality of each node in that…

Discrete Mathematics · Computer Science 2019-08-08 Benjamin Bumpus , Patrick Prosser , James Trimble

It is known that PQ-symmetric maps on the boundary characterize the quasi-isometry type of visual hyperbolic spaces, in particular, of geodesically complete \br-trees. We define a map on pairs of PQ-symmetric ultrametric spaces which…

Geometric Topology · Mathematics 2010-02-08 Álvaro Martínez-Pérez

In this paper, we study metric trees, without any finiteness restrictions. For subsets of such trees, a condition that guarantees that the Hausdorff and Gromov--Hausdorff distances from the subset to the entire metric tree are the same is…

Metric Geometry · Mathematics 2024-12-30 A. O. Ivanov , I. N. Mikhailov , A. A. Tuzhilin

Let B be a finite collection of geometric (not necessarily convex) bodies in the plane. Clearly, this class of geometric objects naturally generalizes the class of disks, lines, ellipsoids, and even convex polygons. We consider geometric…

Discrete Mathematics · Computer Science 2013-08-29 Alexander Grigoriev , Athanassios Koutsonas , Dimitrios M. Thilikos

A monotone drawing of a graph G is a straight-line drawing of G such that every pair of vertices is connected by a path that is monotone with respect to some direction. Trees, as a special class of graphs, have been the focus of several…

Data Structures and Algorithms · Computer Science 2025-05-19 Anargyros Oikonomou , Antonios Symvonis

We develop a Morse-Lusternik-Schnirelmann theory for the distance between two points of a smoothly embedded circle in a complete Riemannian manifold. This theory suggests very naturally a definition of width that generalises the classical…

Differential Geometry · Mathematics 2025-03-27 Lucas Ambrozio , Rafael Montezuma , Roney Santos

Let $P$ be a set of $n$ points in the plane in general position. We show that at least $\lfloor n/3\rfloor$ plane spanning trees can be packed into the complete geometric graph on $P$. This improves the previous best known lower bound…

Computational Geometry · Computer Science 2019-02-26 Ahmad Biniaz , Alfredo García

A bounded subset of a normed linear space is said to be (diametrically) complete if it cannot be enlarged without increasing the diameter. A complete super set of a bounded set $K$ having the same diameter as $K$ is called a completion of…

Functional Analysis · Mathematics 2018-02-27 Chan He , Horst Martini , Senlin Wu

Treewidth is a graph parameter that plays a fundamental role in several structural and algorithmic results. We study the problem of decomposing a given graph $G$ into node-disjoint subgraphs, where each subgraph has sufficiently large…

Data Structures and Algorithms · Computer Science 2013-04-08 Chandra Chekuri , Julia Chuzhoy