English
Related papers

Related papers: Edge separators for quasi-binary trees

200 papers

A \emph{tree-partition} of a graph $G$ is a proper partition of its vertex set into `bags', such that identifying the vertices in each bag produces a forest. The \emph{tree-partition-width} of $G$ is the minimum number of vertices in a bag…

Combinatorics · Mathematics 2009-04-02 David R. Wood

We determine the maximum distance between any two of the center, centroid, and subtree core among trees with a given order. Corresponding results are obtained for trees with given maximum degree and also for trees with given diameter. The…

Combinatorics · Mathematics 2017-01-20 Heather Smith , László Székely , Hua Wang , Shuai Yuan

The equitable tree-coloring can formulate a structure decomposition problem on the communication network with some security considerations. Namely, an equitable tree-$k$-coloring of a graph is a vertex coloring using $k$ distinct colors…

Combinatorics · Mathematics 2021-04-13 Xin Zhang , Bei Niu , Yan Li , Bi Li

In this paper, we estimate the weak saturation numbers of trees. As a case study, we examine caterpillars and obtain several tight estimates. In particular, this implies that for any $\alpha\in [1,2]$, there exist caterpillars with $k$…

Combinatorics · Mathematics 2026-04-02 Wenchong Chen , Xiao-Chuan Liu , Xu Yang

In this paper, we introduce TreeCoders, a novel family of transformer trees. We moved away from traditional linear transformers to complete k-ary trees. Transformer blocks serve as nodes, and generic classifiers learn to select the best…

Computation and Language · Computer Science 2024-11-12 Pierre Colonna D'Istria , Abdulrahman Altahhan

Let v(G) be the number of vertices and t(G,k) the maximum number of disjoint k-edge trees in G. In this paper we show that (a1) if G is a graph with every vertex of degree at least two and at most s, where s > 3, then t(G,2) is at least…

Combinatorics · Mathematics 2007-05-23 Alexander Kelmans

The tree spanner problem for a graph $G$ is as follows: For a given integer $k$, is there a spanning tree $T$ of $G$ (called a tree $k$-spanner) such that the distance in $T$ between every pair of vertices is at most $k$ times their…

Combinatorics · Mathematics 2025-02-07 Lan Lin , Yixun Lin

Guo, Li, Shangguan, Tamo, and Wootters formulated in SIAM Journal on Computing a hypergraph Nash--Williams--Tutte conjecture: every $k$-weakly-partition-connected hypergraph on $t$ vertices should admit a $k$-distinguishable tree…

Combinatorics · Mathematics 2026-05-28 Yutong Zhang , Yaoran Yang

Let $\T_{n}$ be the set of rooted labeled trees on $\set{0,...,n}$. A maximal decreasing subtree of a rooted labeled tree is defined by the maximal subtree from the root with all edges being decreasing. In this paper, we study a new…

Combinatorics · Mathematics 2022-03-22 Seunghyun Seo , Heesung Shin

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

We look for partition theorems for large subtrees for suitable uncountable trees and colourings. We concentrate on sub-trees of $^{\kappa \ge} 2$ expanded by a well ordering of each level. Unlike earlier works, we do not ask the embedding…

Logic · Mathematics 2026-01-06 Saharon Shelah

We consider three different schemes for signal routing on a tree. The vertices of the tree represent transceivers that can transmit and receive signals, and are equipped with i.i.d. weights representing the strength of the transceivers. The…

Probability · Mathematics 2014-07-14 Maria Deijfen , Nina Gantert

We study the problem of edge partitioning, where the goal is to partition the edge set of a graph into several parts. The replication factor of a vertex $v$ is the number of parts that contain edges incident to $v$. The goal is to minimize…

Discrete Mathematics · Computer Science 2026-05-08 Alexander Yakunin , Andrey Kupavskii , Alexander Sushin , Stanislav Moiseev

For a connected graph, a vertex separator is a set of vertices whose removal creates at least two components and a minimum vertex separator is a vertex separator of least cardinality. The vertex connectivity refers to the size of a minimum…

Data Structures and Algorithms · Computer Science 2013-07-09 Surabhi Jain , N. Sadagopan

For a non-negative integer $\ell$, the $\ell$-leaf power of a tree $T$ is a simple graph $G$ on the leaves of $T$ such that two vertices are adjacent in $G$ if and only if their distance in $T$ is at most $\ell$. We provide a polynomial…

Data Structures and Algorithms · Computer Science 2023-10-24 Jungho Ahn , Eduard Eiben , O-joung Kwon , Sang-il Oum

Let $k\geq2$ be an integer. A tree $T$ is called a $k$-tree if $d_T(v)\leq k$ for each $v\in V(T)$, that is, the maximum degree of a $k$-tree is at most $k$. Let $\lambda_1(D(G))$ denote the distance spectral radius in $G$, where $D(G)$…

Combinatorics · Mathematics 2024-07-22 Sizhong Zhou , Jiancheng Wu

Partially answering a question of Paul Seymour, we obtain a sufficient eigenvalue condition for the existence of $k$ edge-disjoint spanning trees in a regular graph, when $k\in \{2,3\}$. More precisely, we show that if the second largest…

Combinatorics · Mathematics 2013-12-10 Sebastian M. Cioabă , Wiseley Wong

In this paper we investigate the geometric properties of quasi-trees, and prove some equivalent criteria. We give a general construction of a tree that approximates the ends of a geodesic space, and use this to prove that every quasi-tree…

Metric Geometry · Mathematics 2023-08-28 Alice Kerr

Given an undirected graph $G$ whose edge weights change over $s$ time slots, the sub-tree scheduling for wireless sensor networks with partial coverage asks to partition the vertices of $G$ in $s$ non-empty trees such that the total weight…

Computational Complexity · Computer Science 2023-01-03 Michele Barbato , Nicola Bianchessi

We study that over some types of trees with a given number of vertices, which trees minimize or maximize the total number of subtrees. Trees minimizing (resp. maximizing) the total number of subtrees usually maximize (resp. minimize) the…

Combinatorics · Mathematics 2012-04-30 Shuchao Li , Shujing Wang
‹ Prev 1 8 9 10 Next ›