English
Related papers

Related papers: Partition theorems for expanded trees

200 papers

Exploratory data analysis is crucial for developing and understanding classification models from high-dimensional datasets. We explore the utility of a new unsupervised tree ensemble called uncharted forest for visualizing class…

Machine Learning · Statistics 2018-07-03 Casey Kneale , Steven D. Brown

The theme of the first two sections, is to prepare the framework of how from a ``complicated'' family of so called index models $I \in K_1$ we build many and/or complicated structures in a class $K_2$. The index models are…

Logic · Mathematics 2023-05-19 Saharon Shelah

We consider drawings of trees in which all edges incident to leaves can be extended to infinite rays without crossing, partitioning the plane into infinite convex polygons. Among all such drawings we seek the one maximizing the angular…

Computational Geometry · Computer Science 2007-05-23 Josiah Carlson , David Eppstein

This paper investigates some properties of the number of subtrees of a tree with given degree sequence. These results are used to characterize trees with the given degree sequence that have the largest number of subtrees, which generalizes…

Combinatorics · Mathematics 2012-09-04 Xiu-Mei Zhang , Xiao-Dong Zhang , Daniel Gray , Hua Wang

In his recent work, Andrews revisited two-color partitions with certain restrictions on the differences between consecutive parts, and he established three theorems linking these two-color partitions with more familiar kinds of partitions.…

Combinatorics · Mathematics 2022-02-08 Shishuo Fu

We formulate a well-posedness and approximation theory for a class of generalised saddle point problems. In this way we develop an approach to a class of fourth order elliptic partial differential equations using the idea of splitting into…

Numerical Analysis · Mathematics 2019-04-02 Charles M. Elliott , Hans Fritz , Graham Hobbs

We provide information about the asymptotic regimes for a homogeneous fragmentation of a finite set. We establish a phase transition for the asymptotic behaviours of the shattering times, defined as the first instants when all the blocks of…

Probability · Mathematics 2009-05-22 Adrien Joseph

Two kinds of approximation algorithms exist for the k-BALANCED PARTITIONING problem: those that are fast but compute unsatisfying approximation ratios, and those that guarantee high quality ratios but are slow. In this paper we prove that…

Computational Complexity · Computer Science 2019-04-29 Andreas Emil Feldmann

Plane increasing trees are rooted labeled trees embedded into the plane such that the sequence of labels is increasing on any branch starting at the root. Relaxed binary trees are a subclass of unlabeled directed acyclic graphs. We…

Combinatorics · Mathematics 2018-07-12 Michael Wallner

An $r$-augmented tree is a rooted tree plus $r$ edges added from each leaf to ancestors. For $d,g,r\in\mathbb{N}$, we construct a bipartite $r$-augmented complete $d$-ary tree having girth at least $g$. The height of such trees must grow…

Combinatorics · Mathematics 2015-05-01 Noga Alon , Alexandr Kostochka , Benjamin Reiniger , Douglas B. West , Xuding Zhu

Assuming the existence of a strong cardinal $\kappa$ and a measurable cardinal above it, we force a generic extension in which $\kappa$ is a singular strong limit cardinal of any prescribed cofinality, and such that the tree property holds…

Logic · Mathematics 2017-08-08 Mohammad Golshani , Rahman Mohammadpour

The subtrees and BC-subtrees (subtrees where any two leaves are at even distance apart) have been extensively studied in recent years. Such structures, under special constraints on degrees, have applications in many fields. Through an…

Combinatorics · Mathematics 2021-10-08 Yu Yang , Xiao-xiao Li , Meng-yuan Jin , Long Li , Hua Wang , Xiao-Dong Zhang

We construct a homotopy initial functor from the partition complex of a finite set $A$ to a category of trees with leaves labelled by $A$. As an application, this provides an equivalence between different bar constructions of an operad. In…

Algebraic Topology · Mathematics 2021-12-16 Gijs Heuts , Ieke Moerdijk

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

Let $T(n,m)$ be the set of all plane labelled bipartite trees with $n$ white vertices and $m$ black. If the number $n+m$ of vertices is even, then the set $T(n,m)$ is a union of two disjoint subsets --- subset od "even" trees and subset of…

Combinatorics · Mathematics 2016-11-04 Yury Kochetkov

Given a tree of weighted vertices, it is sometimes possible to break the tree into two equally-weighted subtrees within an allowable error. We give a fast algorithm that finds an edge which breaks the tree into equal-weight components or…

Combinatorics · Mathematics 2020-11-13 Corinne Mulvey

This extended abstract is dedicated to the analysis of the height of non-plane unlabelled rooted binary trees. The height of such a tree chosen uniformly among those of size $n$ is proved to have a limiting theta distribution, both in a…

Combinatorics · Mathematics 2008-07-16 Nicolas Broutin , Philippe Flajolet

We study several enumeration problems connected to linear trees, a broad class which includes stars, paths, generalized stars, and caterpillars. We provide generating functions for counting the number of linear trees on $n$ vertices,…

Combinatorics · Mathematics 2020-03-23 Tanay Wakhare , Eric Wityk , Charles R. Johnson

The finite satisfiability problem for the two-variable fragment of first-order logic interpreted over trees was recently shown to be ExpSpace-complete. We consider two extensions of this logic. We show that adding either additional binary…

Logic in Computer Science · Computer Science 2016-11-28 Bartosz Bednarczyk , Witold Charatonik , Emanuel Kieroński

Tree-decompositions and treewidth are of fundamental importance in structural and algorithmic graph theory. The "spread" of a tree-decomposition is the minimum integer $s$ such that every vertex lies in at most $s$ bags. A…

Combinatorics · Mathematics 2026-04-08 Marc Distel , Neel Kaul , Raj Kaul , David R. Wood