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While branching network structures abound in nature, their objective analysis is more difficult than expected because existing quantitative methods often rely on the subjective judgment of branch structures. This problem is particularly…

Algebraic Topology · Mathematics 2024-02-13 Haruhisa Oda , Mayuko Kida , Yoichi Nakata , Hiroki Kurihara

A new global approach in the study of duality transformations is introduced. The geometrical structure of complex line bundles is generalized to higher order U(1) bundles which are classified by quantized charges and duality maps are…

High Energy Physics - Theory · Physics 2008-02-03 M. I. Caicedo , I. Martin , A. Restuccia

We investigate the tractability of a simple fusion of two fundamental structures on graphs, a spanning tree and a perfect matching. Specifically, we consider the following problem: given an edge-weighted graph, find a minimum-weight…

Data Structures and Algorithms · Computer Science 2024-07-12 Kristóf Bérczi , Tamás Király , Yusuke Kobayashi , Yutaro Yamaguchi , Yu Yokoi

Distributions, i.e., subsets of tangent bundles formed by piecing together subspaces of tangent spaces, are commonly encountered in the theory and application of differential geometry. Indeed, the theory of distributions is a fundamental…

Differential Geometry · Mathematics 2023-09-20 Andrew D. Lewis

We study the tractability of conjunctive query answering for queries with unbounded arity. It is well known that tractability of the problem can be characterised in terms of the queries treewidth under the assumption of bounded arity. We…

Databases · Computer Science 2022-06-14 Matthias Lanzinger

Trellises are crucial graphical representations of codes. While conventional trellises are well understood, the general theory of (tail-biting) trellises is still under development. Iterative decoding concretely motivates such theory. In…

Information Theory · Computer Science 2014-02-27 David Conti , Nigel Boston

Recent work has established that large informatics graphs such as social and information networks have non-trivial tree-like structure when viewed at moderate size scales. Here, we present results from the first detailed empirical…

Data Structures and Algorithms · Computer Science 2016-05-04 Aaron B. Adcock , Blair D. Sullivan , Michael W. Mahoney

In this paper, we give a constructive proof of the fact that the treewidth of a graph is at most its divisorial gonality. The proof gives a polynomial time algorithm to construct a tree decomposition of width at most $k$, when an effective…

Discrete Mathematics · Computer Science 2020-05-13 Hans L. Bodlaender , Josse van Dobben de Bruyn , Dion Gijswijt , Harry Smit

In this paper, we develop a coarse analogue of treewidth. We prove that a graph $G$ admits a tree-decomposition in which each bag is contained in the union of a bounded number of balls of bounded radius, if and only if $G$ admits a…

Combinatorics · Mathematics 2025-09-08 Tung Nguyen , Alex Scott , Paul Seymour

In this note we gather the theoretical outlines of three basic algorithms for tangles in abstract separation systems: a naive tree search for finding tangles; an algorithm which outputs a certificate for the non-existence of tangles if…

Combinatorics · Mathematics 2025-05-16 Christian Elbracht , Jay Lilian Kneip , Maximilian Teegen

Treewidth is a well-known graph invariant with multiple interesting applications in combinatorics. On the practical side, many NP-complete problems are polynomial-time (sometimes even linear-time) solvable on graphs of bounded treewidth. On…

Category Theory · Mathematics 2021-05-13 Zoltan A. Kocsis , Benjamin Merlin Bumpus

Phylogenetic trees and networks are leaf-labelled graphs used to model evolution. Display graphs are created by identifying common leaf labels in two or more phylogenetic trees or networks. The treewidth of such graphs is bounded as a…

Data Structures and Algorithms · Computer Science 2018-09-05 Remie Janssen , Mark Jones , Steven Kelk , Georgios Stamoulis , Taoyang Wu

A characterization of the tree $T^*$ such that $\mathrm{BP}(T^*)=\overleftrightarrow{\mathrm{DFUDS}(T)}$, the reversal of $\mathrm{DFUDS}(T)$ is given. An immediate consequence is a rigorous characterization of the tree $\hat{T}$ such that…

Data Structures and Algorithms · Computer Science 2018-04-16 Rayan Chikhi , Alexander Schönhuth

In many modern applications, including analysis of gene expression and text documents, the data are noisy, high-dimensional, and unordered--with no particular meaning to the given order of the variables. Yet, successful learning is often…

Methodology · Statistics 2008-07-25 Ann B. Lee , Boaz Nadler , Larry Wasserman

Contour trees describe the topology of level sets in scalar fields and are widely used in topological data analysis and visualization. A main challenge of utilizing contour trees for large-scale scientific data is their computation at scale…

Computational Geometry · Computer Science 2024-10-01 Mingzhe Li , Hamish Carr , Oliver Rübel , Bei Wang , Gunther H. Weber

Over the past decade, we witness an increasing amount of interest in the design of exact exponential-time and parameterized algorithms for problems in Graph Drawing. Unfortunately, we still lack knowledge of general methods to develop such…

Data Structures and Algorithms · Computer Science 2023-10-10 Siddharth Gupta , Guy Sa'ar , Meirav Zehavi

We present a canonical way to decompose finite graphs into highly connected local parts. The decomposition depends only on an integer parameter whose choice sets the intended degree of locality. The global structure of the graph, as…

Combinatorics · Mathematics 2025-07-01 Reinhard Diestel , Raphael W. Jacobs , Paul Knappe , Jan Kurkofka

In this paper, we introduce complex functional maps, which extend the functional map framework to conformal maps between tangent vector fields on surfaces. A key property of these maps is their orientation awareness. More specifically, we…

Computer Vision and Pattern Recognition · Computer Science 2021-12-20 Nicolas Donati , Etienne Corman , Simone Melzi , Maks Ovsjanikov

It is known that there is a linear dependence between the treewidth of a graph and its balanced separator number: the smallest integer $k$ such that for every weighing of the vertices, the graph admits a balanced separator of size at most…

Supplementary comments about generalized Lie algebroids are presented and a new point of view over the construction of the Lie algebroid generalized tangent bundle of a (dual) vector bundle is introduced. Using the general theory of…

Differential Geometry · Mathematics 2014-11-03 E. Peyghan , C. M. Arcuş , L. Nourmohammadifar
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