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We study the problem of maximizing the number of full degree vertices in a spanning tree $T$ of a graph $G$; that is, the number of vertices whose degree in $T$ equals its degree in $G$. In cubic graphs, this problem is equivalent to…

Combinatorics · Mathematics 2022-11-11 Sarah Acquaviva , Deepak Bal

In Graph Minors III, Robertson and Seymour write: "It seems that the tree-width of a planar graph and the tree-width of its geometric dual are approximately equal - indeed, we have convinced ourselves that they differ by at most one". They…

Discrete Mathematics · Computer Science 2011-12-02 Frédéric Mazoit

Asymptotic behaviour of maximum sizes of induced trees and forests has been studied extensively in last decades, though the overall picture is far from being complete. In this paper, we close several significant gaps: 1) We prove $2$-point…

Combinatorics · Mathematics 2024-08-28 Margarita Akhmejanova , Vladislav Kozhevnikov , Maksim Zhukovskii

In 1989, Zehavi and Itai conjectured that every $k$-connected graph contains $k$ independent spanning trees rooted at any prescribed vertex $r$. That is, for each vertex $v$, the unique $r$-$v$ paths within these $k$ spanning trees are…

It is well-known that the Vertex Cover problem is in P on bipartite graphs, however; the computational complexity of the Partial Vertex Cover problem on bipartite graphs is open. In this paper, we first show that the Partial Vertex Cover…

Computational Complexity · Computer Science 2013-04-23 Bugra Caskurlu , K. Subramani

We study a model of growing planar tree graphs where in each time step we separate the tree into two components by splitting a vertex and then connect the two pieces by inserting a new link between the daughter vertices. This model…

Statistical Mechanics · Physics 2009-11-13 Francois David , Mark Dukes , Thordur Jonsson , Sigurdur Orn Stefansson

We introduce and study a new graph representation where vertices are embedded in three or more dimensions, and in which the edges are drawn on the projections onto the axis-parallel planes. We show that the complete graph on $n$ vertices…

Discrete Mathematics · Computer Science 2020-10-06 N. R. Aravind , Udit Maniyar

In 1995, Koml\'os, S\'ark\"ozy and Szemer\'edi showed that every large $n$-vertex graph with minimum degree at least $(1/2 + \gamma)n$ contains all spanning trees of bounded degree. We consider a generalization of this result to loose…

Combinatorics · Mathematics 2024-05-03 Yanitsa Pehova , Kalina Petrova

Among many topological indices of trees the sum of distances $\sigma(T)$ and the number of subtrees $F(T)$ have been a long standing pair of graph invariants that are well known for their negative correlation. That is, among various given…

Combinatorics · Mathematics 2017-12-05 Shuchao Li , Hua Wang , Shujing Wang

We consider the problem of coloring the squares of graphs of bounded maximum average degree, that is, the problem of coloring the vertices while ensuring that two vertices that are adjacent or have a common neighbour receive different…

Discrete Mathematics · Computer Science 2013-08-21 Marthe Bonamy , Benjamin Lévêque , Alexandre Pinlou

The seminal papers of Edmonds \cite{Egy}, Nash-Williams \cite{NW} and Tutte \cite{Tu} have laid the foundations of the theories of packing arborescences and packing trees. The directed version has been extensively investigated, resulting in…

Combinatorics · Mathematics 2024-11-26 Pierre Hoppenot , Mathis Martin , Zoltán Szigeti

Given a subgraph $H$ of a graph $G$, the induced graph of $H$ is the largest subgraph of $G$ whose vertex set is the same as that of $H$. Our paper concerns the induced graphs of the components of $\operatorname{WSF}(G)$, the wired spanning…

Probability · Mathematics 2020-03-18 Russell Lyons , Yuval Peres , Xin Sun

Given a graph, we can form a spanning forest by first sorting the edges in some order, and then only keep edges incident to a vertex which is not incident to any previous edge. The resulting forest is dependent on the ordering of the edges,…

Combinatorics · Mathematics 2018-02-16 Steve Butler , Misa Hamanaka , Marie Hardt

We consider 15 properties of labeled random graphs that are of interest in the graph-theoretical and the graph mining literature, such as clustering coefficients, centrality measures, spectral radius, degree assortativity, treedepth,…

Social and Information Networks · Computer Science 2022-06-24 Hang Chen , Vahan Huroyan , Stephen Kobourov , Myroslav Kryven

We prove that, if $m$ is sufficiently large, every graph on $m+1$ vertices that has a universal vertex and minimum degree at least $\lfloor \frac{2m}{3} \rfloor$ contains each tree $T$ with $m$ edges as a subgraph. Our result confirms, for…

Combinatorics · Mathematics 2022-07-21 Bruce Reed , Maya Stein

In a fractional coloring, vertices of a graph are assigned measurable subsets of the real line and adjacent vertices receive disjoint subsets; the fractional chromatic number of a graph is at most $k$ if it has a fractional coloring in…

Combinatorics · Mathematics 2024-07-25 Tom Kelly , Luke Postle

In the first paper of the Graph Minors series [JCTB '83], Robertson and Seymour proved the Forest Minor theorem: the $H$-minor-free graphs have bounded pathwidth if and only if $H$ is a forest. In recent years, considerable effort has been…

Combinatorics · Mathematics 2025-12-02 Édouard Bonnet , Benjamin Duhamel , Robert Hickingbotham

A star $k$-coloring is a proper $k$-coloring where the union of two color classes induces a star forest. While every planar graph is 4-colorable, not every planar graph is star 4-colorable. One method to produce a star 4-coloring is to…

Combinatorics · Mathematics 2015-10-13 Axel Brandt , Michael Ferrara , Mohit Kumbhat , Sarah Loeb , Derrick Stolee , Matthew Yancey

For some $k \in \mathbb{Z}_{\geq 0}\cup \infty$, we call a linear forest $k$-bounded if each of its components has at most $k$ edges. We will say a $(k,\ell)$-bounded linear forest decomposition of a graph $G$ is a partition of $E(G)$ into…

Combinatorics · Mathematics 2023-01-30 Rutger Campbell , Florian Hörsch , Benjamin Moore

We recently introduced proportional choosability, a new list analogue of equitable coloring. Like equitable coloring, and unlike list equitable coloring (a.k.a. equitable choosability), proportional choosability bounds sizes of color…

Combinatorics · Mathematics 2018-07-02 Hemanshu Kaul , Jeffrey A. Mudrock , Michael J. Pelsmajer , Benjamin Reiniger
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