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A \emph{metric tree embedding} of expected \emph{stretch~$\alpha \geq 1$} maps a weighted $n$-node graph $G = (V, E, \omega)$ to a weighted tree $T = (V_T, E_T, \omega_T)$ with $V \subseteq V_T$ such that, for all $v,w \in V$,…

Distributed, Parallel, and Cluster Computing · Computer Science 2016-08-25 Stephan Friedrichs , Christoph Lenzen

Quartet Reconstruction, the task of recovering a phylogenetic tree from smaller trees on four species called \textit{quartets}, is a well-studied problem in theoretical computer science with far-reaching connections to statistics, graph…

Data Structures and Algorithms · Computer Science 2026-04-21 Dionysis Arvanitakis , Vaggos Chatziafratis , Yiyuan Luo , Konstantin Makarychev

Graph embeddings have emerged as a powerful tool for representing complex network structures in a low-dimensional space, enabling the use of efficient methods that employ the metric structure in the embedding space as a proxy for the…

Social and Information Networks · Computer Science 2024-04-18 Radosław Nowak , Adam Małkowski , Daniel Cieślak , Piotr Sokół , Paweł Wawrzyński

We define a special case of tree decompositions for planar graphs that respect a given embedding of the graph. We study the analogous width of the resulting decomposition we call the embedded-width of a plane graph. We show both upper…

Discrete Mathematics · Computer Science 2017-03-23 Glencora Borradaile , Jeff Erickson , Hung Le , Robbie Weber

Random geometric graphs are random graph models defined on metric measure spaces. A random geometric graph is generated by first sampling points from a metric space and then connecting each pair of sampled points independently with a…

Probability · Mathematics 2025-11-10 Han Huang , Pakawut Jiradilok , Elchanan Mossel

Rotation distances measure the differences in structure between rooted ordered binary trees. The one-dimensional skeleta of associahedra are rotation graphs, where two vertices representing trees are connected by an edge if they differ by a…

Data Structures and Algorithms · Computer Science 2020-06-29 Sean Cleary , Haris Nadeem

We study the problem of detecting local geometry in random graphs. We introduce a model $\mathcal{G}(n, p, d, k)$, where a hidden community of average size $k$ has edges drawn as a random geometric graph on $\mathbb{S}^{d-1}$, while all…

Statistics Theory · Mathematics 2026-03-26 Jinho Bok , Shuangping Li , Sophie H. Yu

We consider the problem of estimating species trees from unrooted gene tree topologies in the presence of incomplete lineage sorting, a common phenomenon that creates gene tree heterogeneity in multilocus datasets. One popular class of…

Populations and Evolution · Quantitative Biology 2018-12-21 Sebastien Roch

We prove that the treewidth of an Erd\"{o}s-R\'{e}nyi random graph $\rg{n, m}$ is, with high probability, greater than $\beta n$ for some constant $\beta > 0$ if the edge/vertex ratio $\frac{m}{n}$ is greater than 1.073. Our lower bound…

Discrete Mathematics · Computer Science 2009-08-03 Yong Gao

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

By definition, a rigid graph in $\mathbb{R}^d$ (or on a sphere) has a finite number of embeddings up to rigid motions for a given set of edge length constraints. These embeddings are related to the real solutions of an algebraic system.…

Combinatorics · Mathematics 2021-10-26 Evangelos Bartzos , Ioannis Z. Emiris , Raimundas Vidunas

The emergence of massive graph data sets requires fast mining algorithms. Centrality measures to identify important vertices belong to the most popular analysis methods in graph mining. A measure that is gaining attention is forest…

Data Structures and Algorithms · Computer Science 2021-01-18 Alexander van der Grinten , Eugenio Angriman , Maria Predari , Henning Meyerhenke

We propose a novel architecture for Graph Neural Networks that is inspired by the idea behind Tree Kernels of measuring similarity between trees by taking into account their common substructures, named fragments. By imposing a series of…

Computation and Language · Computer Science 2021-10-04 Federico Ruggeri , Marco Lippi , Paolo Torroni

Nearest neighbor search supports important applications in many domains, such as database, machine learning, computer vision. Since the computational cost for accurate search is too high, the community turned to the research of approximate…

Information Retrieval · Computer Science 2022-01-11 Xiaobin Fan , Xiaoping Wang , Kai Lu , Lei Xue , Jinjing Zhao

We give almost-linear-time algorithms for approximating rooted minimum cut and maximum arborescence packing in directed graphs, two problems that are dual to each other [Edm73]. More specifically, for an $n$-vertex, $m$-edge directed graph…

Data Structures and Algorithms · Computer Science 2025-12-18 Yonggang Jiang , Yaowei Long , Thatchaphol Saranurak , Benyu Wang

Computing bounded depth decompositions is a bottleneck in many applications of the treedepth parameter. The fastest known algorithm, which is due to Reidl, Rossmanith, S\'{a}nchez Villaamil, and Sikdar [ICALP 2014], runs in…

Data Structures and Algorithms · Computer Science 2025-02-25 Lars Jaffke , Paloma T. de Lima , Wojciech Nadara , Emmanuel Sam

Compatibility of unrooted phylogenetic trees is a well studied problem in phylogenetics. It asks to determine whether for a set of k input trees there exists a larger tree (called a supertree) that contains the topologies of all k input…

Discrete Mathematics · Computer Science 2014-03-03 Alexander Grigoriev , Steven Kelk , Nela Lekic

Word and graph embeddings are widely used in deep learning applications. We present a data structure that captures inherent hierarchical properties from an unordered flat embedding space, particularly a sense of direction between pairs of…

Computation and Language · Computer Science 2024-11-12 Xingzhi Guo , Steven Skiena

Nearest neighbor search is a fundamental data structure problem with many applications in machine learning, computer vision, recommendation systems and other fields. Although the main objective of the data structure is to quickly report…

Data Structures and Algorithms · Computer Science 2025-02-20 Piyush Anand , Piotr Indyk , Ravishankar Krishnaswamy , Sepideh Mahabadi , Vikas C. Raykar , Kirankumar Shiragur , Haike Xu

Graph-based algorithms have demonstrated state-of-the-art performance in the nearest neighbor search (NN-Search) problem. These empirical successes urge the need for theoretical results that guarantee the search quality and efficiency of…

Machine Learning · Computer Science 2023-03-14 Anshumali Shrivastava , Zhao Song , Zhaozhuo Xu