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Related papers: Plane Triangulations Without Spanning 2-Trees

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A k-tree is either a complete graph on (k+1) vertices or given a k-tree G' with n vertices, a k-tree G with (n+1) vertices can be constructed by introducing a new vertex v and picking a k-clique Q in G' and then joining each vertex u in Q.…

Discrete Mathematics · Computer Science 2011-03-25 Suresh Badarla , R Rama

A bipartite graph $G=(A, B, E)$ is said to be a biconvex bipartite graph if there exist orderings $<_A$ in $A$ and $<_B$ in $B$ such that the neighbors of every vertex in $A$ are consecutive with respect to $<_B$ and the neighbors of every…

Combinatorics · Mathematics 2024-06-04 Dhanyamol Antony , Anita Das , Shirish Gosavi , Dalu Jacob , Shashanka Kulamarva

We introduce a new way to tabulate knots by representing knot diagrams using a pair of planar trees. This pair of trees have their edges labeled by integers, they have no valence 2 vertices, and they have the same number of valence 1…

Geometric Topology · Mathematics 2007-05-23 Lisa Hernandez , Xiao-Song Lin

We study the maximal number of triangulations that a planar set of $n$ points can have, and show that it is at most $30^n$. This new bound is achieved by a careful optimization of the charging scheme of Sharir and Welzl (2006), which has…

Discrete Mathematics · Computer Science 2010-01-03 Micha Sharir , Adam Sheffer

We completely characterize triangulations of the projective plane that have a spanning bipartite quadrangulation subgraph. This is an affirmative answer to a question by K\"undgen and Ramamurthi (J Combin Theory Ser B 85, 307--337, 2002)…

Combinatorics · Mathematics 2026-04-24 Kenta Noguchi

Completely independent spanning trees in a graph $G$ are spanning trees of $G$ such that for any two distinct vertices of $G$, the paths between them in the spanning trees are pairwise edge-disjoint and internally vertex-disjoint. In this…

Combinatorics · Mathematics 2022-09-21 Toru Hasunuma

Triangulations of the 5-gon with no separating triangle nor quadrangle, so called 5c-triangulations, are a planar map family closely related to 5-connected planar triangulations. We show that 5c-triangulations are in bijection with…

Combinatorics · Mathematics 2025-10-29 Éric Fusy

A 1-planar graph is a graph which has a drawing on the plane such that each edge is crossed at most once. If a 1-planar graph is drawn in that way, the drawing is called a {\it 1-plane graph}. A graph is maximal 1-plane (or 1-planar) if no…

Combinatorics · Mathematics 2025-05-01 Zhangdong Ouyang , Yuanqiu Huang , Licheng Zhang , Fengming Dong

Let $G$ be a connected graph of order $n$. A spanning $k$-tree of $G$ is a spanning tree with the maximum degree at most $k$, and a spanning $k$-ended-tree of $G$ is a spanning tree at most $k$ leaves, where $k\geq2$ is an integer. This…

Combinatorics · Mathematics 2025-06-10 Jifu Lin , Zenan Du , Xinghui Zhao , Lihua You

It is known that graphs on n vertices with minimum degree at least 3 have spanning trees with at least n/4+2 leaves and that this can be improved to (n+4)/3 for cubic graphs without the diamond K_4-e as a subgraph. We generalize the second…

Combinatorics · Mathematics 2007-07-19 Paul Bonsma , Florian Zickfeld

In this paper we give an exact analytical expression for the number of spanning trees of an infinite family of outerplanar, small-world and self-similar graphs. This number is an important graph invariant related to different topological…

Combinatorics · Mathematics 2015-06-11 Francesc Comellas , Alicia Miralles , Hongxiao Liu , Zhongzhi Zhang

We present a link-by-link rule-based method for constructing all members of the ensemble of spanning trees for any recursively generated, finitely articulated graph, such as the DGM net. The recursions allow for many large-scale properties…

Physics and Society · Physics 2022-03-14 C. Tyler Diggans , Erik M. Bollt , Daniel ben-Avraham

We introduce and study the {\em orderly spanning trees} of plane graphs. This algorithmic tool generalizes {\em canonical orderings}, which exist only for triconnected plane graphs. Although not every plane graph admits an orderly spanning…

Data Structures and Algorithms · Computer Science 2015-02-06 Yi-Ting Chiang , Ching-Chi Lin , Hsueh-I Lu

A tree with at most $k$ leaves is called a $k$-ended tree. A spanning 2-ended tree is a Hamilton path. A Hamilton cycle can be considered as a spanning 1-ended tree. The earliest result concerning spanning trees with few leaves states that…

Combinatorics · Mathematics 2014-09-09 Zh. G. Nikoghosyan

Raspaud and Wang conjectured that every triangle-free planar graph can be vertex-partitioned into an independent set and a forest. Independently, Kawarabayashi and Thomassen also remarked that this might be true, after providing another…

Combinatorics · Mathematics 2025-11-25 Guanwu Liu , Rongxing Xu

We prove that every 2-sphere graph different from a prism can be vertex 4-colored in such a way that all Kempe chains are forests. This implies the following three tree theorem: the arboricity of a discrete 2-sphere is 3. Moreover, the…

Combinatorics · Mathematics 2023-09-06 Oliver Knill

We show that 4-connected plane triangulations can be redrawn such that edges are represented by straight segments and the vertices are covered by a set of at most $\sqrt{2n}$ lines each of them horizontal or vertical. The same holds for all…

Combinatorics · Mathematics 2019-08-15 Stefan Felsner

Ply number is a recently developed graph drawing metric inspired by studying road networks. Informally, for each vertex v, which is associated with a point in the plane, a disk is drawn centered on v with a radius that is alpha times the…

Computational Geometry · Computer Science 2018-08-13 Michael T. Goodrich , Timothy Johnson

It implicitly follows from the work of [Colbourn, El-Mallah: On two dual classes of planar graphs. Discrete Mathematics 80(1): 21-40 (1990)] that every planar partial 3-tree is a subgraph of a planar 3-tree. This fact has already enabled to…

Discrete Mathematics · Computer Science 2012-10-31 Jan Kratochvíl , Michal Vaner

We introduce the set of (non-spanning) tree-decorated planar maps, and show that they are in bijection with the Cartesian product between the set of trees and the set of maps with a simple boundary. As a consequence, we count the number of…

Combinatorics · Mathematics 2020-04-09 Luis Fredes , Avelio Sepúlveda
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