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Loebl, Koml\'os and S\'os conjectured that every $n$-vertex graph $G$ with at least $n/2$ vertices of degree at least $k$ contains each tree $T$ of order $k+1$ as a subgraph. We give a sketch of a proof of the approximate version of this…

Combinatorics · Mathematics 2017-07-31 Jan Hladky , Diana Piguet , Miklos Simonovits , Maya Stein , Endre Szemeredi

A $k$-bisection of a bridgeless cubic graph $G$ is a $2$-colouring of its vertex set such that the colour classes have the same cardinality and all connected components in the two subgraphs induced by the colour classes (monochromatic…

Combinatorics · Mathematics 2018-09-11 Marien Abreu , Jan Goedgebeur , Domenico Labbate , Giuseppe Mazzuoccolo

For intractable problems on graphs of bounded treewidth, two graph parameters treedepth and vertex cover number have been used to obtain fine-grained complexity results. Although the studies in this direction are successful, we still need a…

Data Structures and Algorithms · Computer Science 2023-04-03 Tatsuya Gima , Tesshu Hanaka , Masashi Kiyomi , Yasuaki Kobayashi , Yota Otachi

We prove that the wired uniform spanning forest exhibits mean-field behaviour on a very large class of graphs, including every transitive graph of at least quintic volume growth and every bounded degree nonamenable graph. Several of our…

Probability · Mathematics 2019-05-31 Tom Hutchcroft

An old problem of Erd\H{o}s, Fajtlowicz and Staton asks for the order of a largest induced regular subgraph that can be found in every graph on n vertices. Motivated by this problem, we consider the order of such a subgraph in a typical…

Combinatorics · Mathematics 2008-08-15 Michael Krivelevich , Benny Sudakov , Nicholas Wormald

We prove a lower bound on the number of spanning two-forests in a graph, in terms of the number of vertices, edges, and spanning trees. This implies an upper bound on the average cut size of a random two-forest. The main tool is an identity…

Combinatorics · Mathematics 2023-08-09 Harry Richman , Farbod Shokrieh , Chenxi Wu

The topic is the average order of a connected induced subgraph of a graph. This generalizes, to graphs in general, the average order of a subtree of a tree. In 1984, Jamison proved that the average order, over all trees of order $n$, is…

Combinatorics · Mathematics 2021-03-30 Andrew Vince

Equitable list arboricity, introduced by Zhang in 2016, generalizes the notion of equitable list coloring by requiring the subgraph induced by each color class to be acyclic (instead of edgeless) in addition to the usual upper bound on the…

Combinatorics · Mathematics 2021-06-03 Hemanshu Kaul , Jeffrey A. Mudrock , Michael J. Pelsmajer

We define a special case of tree decompositions for planar graphs that respect a given embedding of the graph. We study the analogous width of the resulting decomposition we call the embedded-width of a plane graph. We show both upper…

Discrete Mathematics · Computer Science 2017-03-23 Glencora Borradaile , Jeff Erickson , Hung Le , Robbie Weber

A long-standing conjecture asserts that there exists a constant $c>0$ such that every graph of order $n$ without isolated vertices contains an induced subgraph of order at least $cn$ with all degrees odd. Scott (1992) proved that every…

Combinatorics · Mathematics 2017-07-18 Xinmin Hou , Lei Yu , Jiaao Li , Boyuan Liu

Consider the following process on a simple graph without isolated vertices: Order the edges randomly and keep an edge if and only if it contains a vertex which is not contained in some preceding edge. The resulting set of edges forms a…

Combinatorics · Mathematics 2017-09-12 Zhanar Berikkyzy , Steve Butler , Jay Cummings , Kristin Heysse , Paul Horn , Ruth Luo , Brent Moran

A $(q,t)$\emph{-tree-coloring} of a graph $G$ is a $q$-coloring of vertices of $G$ such that the subgraph induced by each color class is a forest of maximum degree at most $t.$ A $(q,\infty)$\emph{-tree-coloring} of a graph $G$ is a…

Combinatorics · Mathematics 2016-03-31 Keaitsuda Maneeruk Nakprasit , Kittikorn Nakprasit

We prove a common generalization of the celebrated Sauer-Spencer packing theorem and a theorem of Brandt concerning finding a copy of a tree inside a graph. This proof leads to the characterization of the extremal graphs in the case of…

Combinatorics · Mathematics 2021-11-29 Hemanshu Kaul , Benjamin Reiniger

A \emph{linear $k$-forest} is a forest whose components are paths of length at most $k$. The \emph{linear $k$-arboricity} of a graph $G$, denoted by ${\rm la}_k(G)$, is the least number of linear $k$-forests needed to decompose $G$.…

Combinatorics · Mathematics 2016-03-15 Yaping Mao , Zhiwei Guo , Nan Jia , He Li

An equitable tree-$k$-coloring of a graph is a vertex $k$-coloring such that each color class induces a forest and the size of any two color classes differ by at most one. In this work, we show that every interval graph $G$ has an equitable…

Combinatorics · Mathematics 2020-03-10 Bei Niu , Bi Li , Xin Zhang

Recent work on the structure of social networks and the internet has focussed attention on graphs with distributions of vertex degree that are significantly different from the Poisson degree distributions that have been widely studied in…

Statistical Mechanics · Physics 2009-10-31 M. E. J. Newman , S. H. Strogatz , D. J. Watts

Borradaile, Le and Sherman-Bennett [Graphs and Combinatorics, 2017] proved that every $n$-vertex $2$-outerplane graph has a set of at least $2n/3$ vertices that induces an outerplane graph. We identify a major flaw in their proof and…

Combinatorics · Mathematics 2026-02-23 Marco D'Elia , Fabrizio Frati

A facial unique-maximum coloring of a plane graph is a proper coloring of the vertices using positive integers such that each face has a unique vertex that receives the maximum color in that face. Fabrici and G\"{o}ring (2016) proposed a…

Combinatorics · Mathematics 2020-06-12 Bernard Lidický , Kacy Messerschmidt , Riste Škrekovski

We consider the problem of determining the maximum induced density of a graph H in any graph on n vertices. The limit of this density as n tends to infinity is called the inducibility of H. The exact value of this quantity is known only for…

Combinatorics · Mathematics 2013-07-17 James Hirst

A variant of the Erd\H{o}s-S\'os conjecture, posed by Havet, Reed, Stein and Wood, states that every graph with minimum degree at least $\lfloor 2k/3 \rfloor$ and maximum degree at least $k$ contains a copy of every tree with $k$ edges.…

Combinatorics · Mathematics 2025-12-19 Alexey Pokrovskiy , Leo Versteegen , Ella Williams