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Related papers: Packing spanning trees and the $k$-tree protocol

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The number of spanning trees of a graph $G$, denoted $\tau(G)$, is a well studied graph parameter with numerous connections to other areas of mathematics. In a recent remarkable paper, answering a question of Sedl\'a\v{c}ek from 1969, Chan,…

Combinatorics · Mathematics 2025-08-26 Noga Alon , Matija Bucić , Lior Gishboliner

Given a spanning tree $T$ of a planar graph $G$, the co-tree of $T$ is the spanning tree of the dual graph $G^*$ with edge set $(E(G)-E(T))^*$. Gr\"unbaum conjectured in 1970 that every planar 3-connected graph $G$ contains a spanning tree…

Discrete Mathematics · Computer Science 2024-02-09 Christian Ortlieb , Jens M. Schmidt

We give a short elementary proof of Tutte and Nash-Williams' characterization of graphs with k edge-disjoint spanning trees.

Combinatorics · Mathematics 2012-03-07 Tomáš Kaiser

It is well known that finding extremal values and structures can be hard in weighted graphs. However, if the weights are random, this problem can become way easier. In this paper, we examine the minimal weight of a union of $k$…

Combinatorics · Mathematics 2025-02-13 Dmitry Shabanov , Nikita Zvonkov

Let $G$ be a connected graph and $L(G)$ the set of all integers $k$ such that $G$ contains a spanning tree with exactly $k$ leaves. We show that for a connected graph $G$, the set $L(G)$ is contiguous. It follows from work of Chen, Ren, and…

Combinatorics · Mathematics 2024-11-20 Kenta Noguchi , Carol T. Zamfirescu

We define an algorithm k which takes a connected graph G on a totally ordered vertex set and returns an increasing tree R (which is not necessarily a subtree of G). We characterize the set of graphs G such that k(G)=R. Because this set has…

Combinatorics · Mathematics 2007-05-23 Gus Wiseman

We show that for every graph $G$ that contains two edge-disjoint spanning trees, we can choose two edge-disjoint spanning trees $T_1,T_2$ of $G$ such that $|d_{T_1}(v)-d_{T_2}(v)|\leq 5$ for all $v \in V(G)$. We also prove the more general…

Combinatorics · Mathematics 2022-08-09 Florian Hörsch

We present an explicit connected spanning structure that appears in a random graph just above the connectivity threshold with high probability.

Combinatorics · Mathematics 2021-11-29 Yahav Alon , Michael Krivelevich , Peleg Michaeli

In this paper we examine the classes of graphs whose $K_n$-complements are trees and quasi-threshold graphs and derive formulas for their number of spanning trees; for a subgraph $H$ of $K_n$, the $K_n$-complement of $H$ is the graph…

Discrete Mathematics · Computer Science 2007-05-23 Stavros D. Nikolopoulos , Charis Papadopoulos

For any integer $k\geq1,$ a graph $G$ has a $k$-factor if it contains a $k$-regular spanning subgraph. In this paper we prove a sufficient condition in terms of the number of $r$-cliques to guarantee the existence of a $k$-factor in a graph…

Combinatorics · Mathematics 2023-08-29 Guoyan Ao , Ruifang Liu , Jinjiang Yuan , C. T. Ng , T. C. E. Cheng

Let $S\subseteq V(G)$ and $\pi_{G}(S)$ denote the maximum number $t$ of edge-disjoint paths $P_{1},P_{2},\ldots,P_{t}$ in a graph $G$ such that $V(P_{i})\cap V(P_{j})=S$ for any $i,j\in\{1,2,\ldots,t\}$ and $i\neq j$. If $S=V(G)$, then…

Combinatorics · Mathematics 2024-01-25 Wen-Han Zhu , Rong-Xia Hao , Jou-Ming Chang , Jaeun Lee

Let $G$ be a nontrivial graph with minimum degree $\delta$ and $k$ an integer with $k\ge 2$. In the literature, there are eigenvalue conditions that imply $G$ contains $k$ edge-disjoint spanning trees. We give eigenvalue conditions that…

Combinatorics · Mathematics 2025-04-02 Jin Cai , Bo Zhou

Given a group $G$, we define the power graph $\mathcal{P}(G)$ as follows: the vertices are the elements of $G$ and two vertices $x$ and $y$ are joined by an edge if $\langle x\rangle\subseteq \langle y\rangle$ or $\langle y\rangle\subseteq…

Group Theory · Mathematics 2017-05-16 A. R. Moghaddamfar , S. Rahbariyan , S. Navid Salehy , S. Nima Salehy

We give an affirmative answer to a long-standing conjecture of Thomassen, stating that every sufficiently highly connected graph has a $k$-vertex-connected orientation. We prove that a connectivity of order $O(k^2)$ suffices. As a key tool,…

Combinatorics · Mathematics 2025-03-12 Dániel Garamvölgyi , Tibor Jordán , Csaba Király , Soma Villányi

Let $G$ be a connected graph and let $k$ be a positive integer. Let $T$ be a spanning tree of $G$. The leaf degree of a vertex $v\in V(T)$ is defined as the number of leaves adjacent to $v$ in $T$. The leaf degree of $T$ is the maximum leaf…

Combinatorics · Mathematics 2024-06-12 Sufang Wang , Wei Zhang

We give a proof for sharp estimate for the number of spanning trees using linear algebra and generalize this bound to multigraphs. In addition, we show that this bound is tight for complete graphs. In addition, we give estimates for number…

Combinatorics · Mathematics 2022-12-01 K. V. Chelpanov

We prove a refinement of the tree packing theorem by Tutte/Nash-Williams for finite graphs. This result is used to obtain a similar result for end faithful spanning tree packings in certain infinite graphs and consequently to establish a…

Combinatorics · Mathematics 2013-09-19 Florian Lehner

We consider several problems related to packing forests in graphs. The first one is to find $k$ edge-disjoint forests in a directed graph $G$ of maximal size such that the indegree of each vertex in these forests is at most $k$. We describe…

Data Structures and Algorithms · Computer Science 2026-01-26 Pavel Arkhipov , Vladimir Kolmogorov

Chv\'{a}tal and Erd\"{o}s [Discrete Math. 2 (1972) 111-113] stated that, for an $m$-connected graph $G$, if its independence number $\alpha(G)\leq m-1$, then $G$ is Hamilton-connected. Note that $k$-leaf-connectedness is a natural…

Spectral Theory · Mathematics 2025-07-22 Guoyan Ao , Ruifang Liu , Jinjiang Yuan

We prove that every (6k + 2l, 2k)-connected simple graph contains k rigid and l connected edge-disjoint spanning subgraphs. This implies a theorem of Jackson and Jord\'an [4] and a theorem of Jord\'an [6] on packing of rigid spanning…

Discrete Mathematics · Computer Science 2012-01-19 Joseph Cheriyan , Olivier Durand de Gevigney , Zoltán Szigeti