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Related papers: Decompositions into subgraphs of small diameter

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We consider random sub-graphs of a fixed graph $G=(V,E)$ with large minimum degree. We fix a positive integer $k$ and let $G_k$ be the random sub-graph where each $v\in V$ independently chooses $k$ random neighbors, making $kn$ edges in…

Combinatorics · Mathematics 2014-05-12 Alan Frieze , Tony Johansson

A celebrated conjecture of Tuza states that in any finite graph the minimum size of a cover of triangles by edges is at most twice the maximum size of a set of edge-disjoint triangles. For an $r$-uniform hypergraph ($r$-graph) $G$, let…

Combinatorics · Mathematics 2024-05-15 Abdul Basit , David Galvin

In a series of four papers we prove the following relaxation of the Loebl-Komlos-Sos Conjecture: For every $\alpha>0$ there exists a number $k_0$ such that for every $k>k_0$ every $n$-vertex graph $G$ with at least $(\frac12+\alpha)n$…

Combinatorics · Mathematics 2017-07-31 Jan Hladký , János Komlós , Diana Piguet , Miklós Simonovits , Maya J. Stein , Endre Szemerédi

For a graph $G$, let $cp(G)$ denote the minimum number of cliques of $G$ needed to cover the edges of $G$ exactly once. Similarly, let $bp_k(G)$ denote the minimum number of bicliques (i.e. complete bipartite subgraphs of $G$) needed to…

Combinatorics · Mathematics 2020-05-07 Dhruv Rohatgi , John C. Urschel , Jake Wellens

The thickness $\theta(G)$ of a graph $G$ is the minimum number of planar spanning subgraphs into which the graph $G$ can be decomposed. It is a topological invariant of a graph, which was defined by W.T. Tutte in 1963 and also has important…

Combinatorics · Mathematics 2012-02-10 Yan Yang

Many load balancing problems that arise in scientific computing applications ask to partition a graph with weights on the vertices and costs on the edges into a given number of almost equally-weighted parts such that the maximum boundary…

Data Structures and Algorithms · Computer Science 2007-05-23 David Steurer

A set of vertices in a graph is a Hamiltonian subset if it induces a subgraph containing a Hamiltonian cycle. Kim, Liu, Sharifzadeh and Staden proved that among all graphs with minimum degree $d$, $K_{d+1}$ minimises the number of…

Combinatorics · Mathematics 2023-01-19 Stijn Cambie , Jun Gao , Hong Liu

The "separation dimension" of a graph $G$ is the minimum positive integer $d$ for which there is an embedding of $G$ into $\mathbb{R}^d$, such that every pair of disjoint edges are separated by some axis-parallel hyperplane. We prove a…

Combinatorics · Mathematics 2021-07-01 Alex Scott , David R. Wood

We study the problem of detecting the presence of an underlying high-dimensional geometric structure in a random graph. Under the null hypothesis, the observed graph is a realization of an Erd\H{o}s-R\'enyi random graph $G(n,p)$. Under the…

Statistics Theory · Mathematics 2015-11-24 Sébastien Bubeck , Jian Ding , Ronen Eldan , Miklós Rácz

We study the number of edge-disjoint Hamilton cycles one can guarantee in a sufficiently large graph G on n vertices with minimum degree d = (1/2+a)n. For any constant a > 0, we give an optimal answer in the following sense: let…

Combinatorics · Mathematics 2012-11-15 Daniela Kühn , John Lapinskas , Deryk Osthus

For natural numbers $n$ and $k$ ($n > 2k$), a generalized Petersen graph $P(n,k)$, is defined by vertex set $\lbrace u_i,v_i\rbrace$ and edge set $\lbrace u_iu_{i+1},u_iv_i,v_iv_{i+k}\rbrace$; where $i = 1,2,\dots,n$ and subscripts are…

Discrete Mathematics · Computer Science 2010-08-20 Babak Behsaz , Pooya Hatami , Ebadollah S. Mahmoodian

In 1984, Thomassen conjectured that for every constant $k \in \mathbb{N}$, there exists $d$ such that every graph with average degree at least $d$ contains a balanced subdivision of a complete graph on $k$ vertices, i.e. a subdivision in…

Combinatorics · Mathematics 2023-02-09 Yan Wang

We use the polynomial method of Guth and Katz to establish stronger and {\it more efficient} regularity and density theorems for such $k$-uniform hypergraphs $H=(P,E)$, where $P$ is a finite point set in ${\mathbb R}^d$, and the edge set…

Computational Geometry · Computer Science 2024-08-15 Natan Rubin

Let $G$ be a graph on $n$ vertices and $(H,+)$ be an abelian group. What is the minimum size ${\sf S}_H(G)$ of the set of all sums $A(u)+A(v)$ over all injections $A:V(G)\to H$? In 2012, the first author, Angel, the second author, and…

Combinatorics · Mathematics 2025-08-04 Noga Alon , Itai Benjamini , Georgii Zakharov , Maksim Zhukovskii

A set of vertices of a graph $G$ is said to be decycling if its removal leaves an acyclic subgraph. The size of a smallest decycling set is the decycling number of $G$. Generally, at least $\lceil(n+2)/4\rceil$ vertices have to be removed…

Combinatorics · Mathematics 2023-09-22 Roman Nedela , Michaela Seifrtová , Martin Škoviera

Consider a uniform expanders family G_n with a uniform bound on the degrees. It is shown that for any p and c>0, a random subgraph of G_n obtained by retaining each edge, randomly and independently, with probability p, will have at most one…

Probability · Mathematics 2007-05-23 Noga Alon , Itai Benjamini , Alan Stacey

We prove that if an $n$-vertex graph $G$ is non-extremal and $T$ is a bounded degree tree on $n$ vertices, then $T\subset G$ even when the minimum degree of $G$ is less than $n/2$ by a linear term. We avoid the use of the Regularity lemma,…

Combinatorics · Mathematics 2026-05-29 Béla Csaba

An $n$-vertex graph $G$ is locally dense if every induced subgraph of size larger than $\zeta n$ has density at least $d > 0$, for some parameters $\zeta, d > 0$. We show that the number of induced subgraphs of $G$ with $m$ vertices and…

Combinatorics · Mathematics 2024-10-29 Rajko Nenadov

Erd\H{o}s conjectured that every triangle-free graph $G$ on $n$ vertices contains a set of $\lfloor n/2 \rfloor$ vertices that spans at most $n^2 /50$ edges. Krivelevich proved the conjecture for graphs with minimum degree at least…

Combinatorics · Mathematics 2015-02-12 Sergey Norin , Liana Yepremyan

Given a finite simple undirected graph $G$, let $T_1(G)$ denote the subset of vertices of $G$ such that every vertex of $T_1(G)$ belongs to at least one subgraph isomorphic to a graph obtained by connecting a single vertex to two vertices…

Combinatorics · Mathematics 2025-09-30 Peichao Wei , Muhuo Liu , Yang Wu , Zoran Stani\' c