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A graph in which all minimal zero forcing sets are in fact minimum size is called ``well-forced." This paper characterizes well-forced trees and presents an algorithm for determining which trees are well-forced. Additionally, we…

Combinatorics · Mathematics 2023-12-25 Cheryl Grood , Ruth Haas , Bonnie Jacob , Erika King , Shahla Nasserasr

We derive two formulas for the weighted sums of rooted spanning forests of particular sequence of graphs by using the matrix tree theorem. We consider cycle graphs with edges so called the pendant edges. One of our formula can be described…

Combinatorics · Mathematics 2024-02-13 Hajime Fujita , Kimiko Hasegawa , Yukie Inaba , Takefumi Kondo

Much of the information about the multi-valley structure of disordered spin systems can be convened in a simple tree structure -- a barrier tree -- the leaves and internal nodes of which represent, respectively, the local minima and the…

Disordered Systems and Neural Networks · Physics 2009-11-10 Wim Hordijk , Jose F. Fontanari , Peter F. Stadler

We prove a lower bound on the number of spanning two-forests in a graph, in terms of the number of vertices, edges, and spanning trees. This implies an upper bound on the average cut size of a random two-forest. The main tool is an identity…

Combinatorics · Mathematics 2023-08-09 Harry Richman , Farbod Shokrieh , Chenxi Wu

We study graph estimation and density estimation in high dimensions, using a family of density estimators based on forest structured undirected graphical models. For density estimation, we do not assume the true distribution corresponds to…

Machine Learning · Statistics 2010-10-21 Han Liu , Min Xu , Haijie Gu , Anupam Gupta , John Lafferty , Larry Wasserman

A spanning tree of an unweighted graph is a minimum average stretch spanning tree if it minimizes the ratio of sum of the distances in the tree between the end vertices of the graph edges and the number of graph edges. We consider the…

Data Structures and Algorithms · Computer Science 2014-04-15 N. S. Narayanaswamy , G. Ramakrishna

We prove that every oriented tree on $n$ vertices with bounded maximum degree appears as a spanning subdigraph of every directed graph on $n$ vertices with minimum semidegree at least $n/2+o(n)$. This can be seen as a directed graph…

Combinatorics · Mathematics 2026-05-20 Richard Mycroft , Tássio Naia

We give combinatorial criteria for predicting the transcendental weight of Feynman integrals of certain graphs in $\phi^4$ theory. By studying spanning forest polynomials, we obtain operations on graphs which are weight-preserving, and a…

Mathematical Physics · Physics 2011-01-17 Francis Brown , Karen Yeats

We present an algorithm that, with high probability, generates a random spanning tree from an edge-weighted undirected graph in $\tilde{O}(n^{4/3}m^{1/2}+n^{2})$ time (The $\tilde{O}(\cdot)$ notation hides $\operatorname{polylog}(n)$…

Data Structures and Algorithms · Computer Science 2017-06-22 David Durfee , Rasmus Kyng , John Peebles , Anup B. Rao , Sushant Sachdeva

We present a new algorithm, which solves the problem of distributively finding a minimum diameter spanning tree of any (non-negatively) real-weighted graph $G = (V,E,\omega)$. As an intermediate step, we use a new, fast, linear-time…

Distributed, Parallel, and Cluster Computing · Computer Science 2013-12-12 Marc Bui , Franck Butelle , Christian Lavault

Two problems in the search of metric characteristics on weighted undirected graphs with non-negative edge weights are being considered. The first problem: a weighted undirected graph with non-negative edge weight is given. The radius,…

Data Structures and Algorithms · Computer Science 2012-09-24 Airat Urakov , Timofey Timeryaev

Python implementation of selected weighted graph algorithms is presented. The minimal graph interface is defined together with several classes implementing this interface. Graph nodes can be any hashable Python objects. Directed edges are…

Data Structures and Algorithms · Computer Science 2016-01-11 A. Kapanowski , Ł. Gałuszka

Recently we submitted a paper, whose title is A New Fast Unweighted All-pairs Shortest Path Search Algorithm Based on Pruning by Shortest Path Trees, to arXiv. This is related to unweighted graphs. This paper also presents a new fast…

Data Structures and Algorithms · Computer Science 2019-08-20 Yasuo Yamane , Kenichi Kobayashi

Working with tree graphs is always easier than with loopy ones and spanning trees are the closest tree-like structures to a given graph. We find a correspondence between the solutions of random K-satisfiability problem and those of spanning…

Disordered Systems and Neural Networks · Physics 2009-11-11 A. Ramezanpour , S. Moghimi-Araghi

Distribution grids refer to the part of the power grid that delivers electricity from substations to the loads. Structurally a distribution grid is operated in one of several radial/tree-like topologies that are derived from an original…

Optimization and Control · Mathematics 2016-03-08 Deepjyoti Deka , Scott Backhaus , Michael Chertkov

In this paper, we study the problem of finding a minimum weight spanning tree that contains each vertex in a given subset $V_{\rm NT}$ of vertices as an internal vertex. This problem, called Minimum Weight Non-Terminal Spanning Tree,…

Data Structures and Algorithms · Computer Science 2025-01-30 Tesshu Hanaka , Yasuaki Kobayashi

We study the properties of several proximity measures for the vertices of weighted multigraphs and multidigraphs. Unlike the classical distance for the vertices of connected graphs, these proximity measures are applicable to weighted…

Combinatorics · Mathematics 2007-05-23 Pavel Chebotarev , Elena Shamis

We introduce a graph partitioning problem motivated by computational topology and propose two algorithms that produce approximate solutions. Specifically, given a weighted, undirected graph $G$ and a positive integer $k$, we desire to find…

Combinatorics · Mathematics 2019-07-04 Abdel-Rahman Madkour , Phillip Nadolny , Matthew Wright

The matrices of spanning rooted forests are studied as a tool for analysing the structure of digraphs and measuring their characteristics. The problems of revealing the basis bicomponents, measuring vertex proximity, and ranking from…

Combinatorics · Mathematics 2007-05-23 Pavel Chebotarev , Rafig Agaev

We describe recent achievements in the theory of weight systems, which are functions on chord diagrams satisfying so-called $4$-term relations. Our main attention is devoted to constructions of weight systems. The two main sources of these…

Combinatorics · Mathematics 2023-02-24 Maxim Kazaryan , Sergei Lando