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We give new decomposition theorems for classes of graphs that can be transduced in first-order logic from classes of sparse graphs -- more precisely, from classes of bounded expansion and from nowhere dense classes. In both cases, the…

Logic in Computer Science · Computer Science 2022-01-27 Jan Dreier , Jakub Gajarský , Sandra Kiefer , Michał Pilipczuk , Szymon Toruńczyk

A unit disk intersection representation (UDR) of a graph $G$ represents each vertex of $G$ as a unit disk in the plane, such that two disks intersect if and only if their vertices are adjacent in $G$. A UDR with interior-disjoint disks is…

Computational Geometry · Computer Science 2021-08-27 Sujoy Bhore , Maarten Löffler , Soeren Nickel , Martin Nöllenburg

We study random typical minimal factorizations of the $n$-cycle into transpositions, which are factorizations of $(1, \ldots,n)$ as a product of $n-1$ transpositions. By viewing transpositions as chords of the unit disk and by reading them…

Probability · Mathematics 2018-12-04 Valentin Féray , Igor Kortchemski

Given a subshift over an arbitrary alphabet, we construct a representation of the associated unital algebra. We describe a criteria for the faithfulness of this representation in terms of the existence of cycles with no exits. Subsequently,…

Rings and Algebras · Mathematics 2023-06-29 Daniel Gonçalves , Danilo Royer

For a weighted digraph without loops $V$, the arc weights of which can be obtained from an undirected graph with loops ${\sf P}$ according to the rule $v_{ij}=p_{ij}-p_{ii}$, the properties are studied. An effective algorithm for…

Combinatorics · Mathematics 2025-04-22 Vasily Buslov

General treebank analyses are graph structured, but parsers are typically restricted to tree structures for efficiency and modeling reasons. We propose a new representation and algorithm for a class of graph structures that is flexible…

Computation and Language · Computer Science 2020-06-05 Jonathan K. Kummerfeld , Dan Klein

A classical result, fundamental to evolutionary biology, states that an edge-weighted tree $T$ with leaf set $X$, positive edge weights, and no vertices of degree 2 can be uniquely reconstructed from the set of leaf-to-leaf distances…

Populations and Evolution · Quantitative Biology 2011-07-15 A. W. M. Dress , K. T. Huber , M. Steel

A factor graph of a point process is a graph whose vertices are the points of the process, and which is constructed from the process in a deterministic isometry-invariant way. We prove that the d-dimensional Poisson process has a one-ended…

Probability · Mathematics 2007-05-23 Alexander E. Holroyd , Yuval Peres

We introduce the notion of doubly rooted plane trees and give a decomposition of these trees, called the butterfly decomposition which turns out to have many applications. From the butterfly decomposition we obtain a one-to-one…

Combinatorics · Mathematics 2007-05-23 William Y. C. Chen , Nelson Y. Li , Louis W. Shapiro

Phylogenetic trees are a central tool in understanding evolution. They are typically inferred from sequence data, and capture evolutionary relationships through time. It is essential to be able to compare trees from different data sources…

Populations and Evolution · Quantitative Biology 2017-10-31 Michelle Kendall , Caroline Colijn

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

It is a classical result that an unrooted tree $T$ having positive real-valued edge lengths and no vertices of degree two can be reconstructed from the induced distance between each pair of leaves. Moreover, if each non-leaf vertex of $T$…

Combinatorics · Mathematics 2017-07-26 Stefan Gruenewald , Katharina T. Huber , Vincent Moulton , Mike Steel

The Replica Fourier Transform is the generalization of the discrete Fourier Transform to quantities defined on an ultrametric tree. It finds use in con- junction of the replica method used to study thermodynamics properties of disordered…

Disordered Systems and Neural Networks · Physics 2014-12-16 A. Crisanti , C. De Dominicis

A $k$-block in a graph $G$ is a maximal set of at least $k$ vertices no two of which can be separated in $G$ by removing less than $k$ vertices. It is separable if there exists a tree-decomposition of adhesion less than $k$ of $G$ in which…

Combinatorics · Mathematics 2015-06-10 Johannes Carmesin , Pascal Gollin

We show that all permutations in $S_n$ can be generated by affine unicritical polynomials. We use the $\operatorname{PGL}$ group structure to compute the cycle structure of permutations with low Carlitz rank. The tree structure of the group…

Number Theory · Mathematics 2021-03-22 Anna Chlopecki , Juliano Levier-Gomes , Wayne Peng , Alex Shearer , Adam Towsley

Traditionally, reconfiguration problems ask the question whether a given solution of an optimization problem can be transformed to a target solution in a sequence of small steps that preserve feasibility of the intermediate solutions. In…

Discrete Mathematics · Computer Science 2019-01-25 Mark de Berg , Bart M. P. Jansen , Debankur Mukherjee

Given a distance matrix consisting of pairwise distances between species, a distance-based phylogenetic reconstruction method returns a tree metric or equidistant tree metric (ultrametric) that best fits the data. We investigate…

Combinatorics · Mathematics 2017-02-20 Daniel Irving Bernstein , Colby Long

Rotation distance between rooted binary trees measures the number of simple operations it takes to transform one tree into another. There are no known polynomial-time algorithms for computing rotation distance. We give an efficient,…

Data Structures and Algorithms · Computer Science 2018-03-19 Sean Cleary , Katherine St. John

Graph transformation is the rule-based modification of graphs, and is a discipline dating back to the 1970s. In general, to match the left-hand graph of a fixed rule within a host graph requires polynomial time, but to improve matching…

Logic in Computer Science · Computer Science 2021-01-05 Graham Campbell , Detlef Plump

Trees fill many extremal roles in graph theory, being minimally connected and serving a critical role in the definition of $n$-good graphs. In this article, we consider the generalization of trees to the setting of $r$-uniform hypergraphs…

Combinatorics · Mathematics 2017-10-17 Mark Budden , Andrew Penland
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