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When $k|n$, the tree $\mathrm{Comb}_{n,k}$ consists of a path containing $n/k$ vertices, each of whose vertices has a disjoint path length $k-1$ beginning at it. We show that, for any $k=k(n)$ and $\epsilon>0$, the binomial random graph…

Combinatorics · Mathematics 2014-05-27 Richard Montgomery

We consider high-order connectivity in $k$-uniform hypergraphs defined as follows: Two $j$-sets are $j$-connected if there is a walk of edges between them such that two consecutive edges intersect in at least $j$ vertices. We describe the…

Combinatorics · Mathematics 2017-04-20 Oliver Cooley , Mihyun Kang , Christoph Koch

Let a_1,...,a_k satisfy a_1+...+a_k=1 and suppose a k-uniform hypergraph on n vertices satisfies the following property; in any partition of its vertices into k sets A_1,...,A_k of sizes a_1*n,...,a_k*n, the number of edges intersecting…

Combinatorics · Mathematics 2010-02-02 Asaf Shapira , Raphael Yuster

The non-backtracking operator of a graph is a powerful tool in spectral graph theory and random matrix theory. Most existing results for the non-backtracking operator of a random graph concern only eigenvalues or top eigenvectors. In this…

Probability · Mathematics 2024-05-29 Xiangyi Zhu , Yizhe Zhu

Random $s$-intersection graphs have recently received considerable attention in a wide range of application areas. In such a graph, each vertex is equipped with a set of items in some random manner, and any two vertices establish an…

Physics and Society · Physics 2015-02-03 Jun Zhao , Osman Yağan , Virgil Gligor

Let $G=(V,E)$ be a $d$-regular graph on $n$ vertices and let $\mu_0$ be a probability measure on $V$. The act of moving to a randomly chosen neighbor leads to a sequence of probability measures supported on $V$ given by $\mu_{k+1} = A…

Combinatorics · Mathematics 2022-06-14 Stefan Steinerberger , Rekha R. Thomas

Let $ H $ be a multi-digraph on $ h $ vertices with $ q $ arcs. An \textbf{$H$-subdivision} in a digraph $D$ is a subdigraph obtained by replacing every arc $uv$ of $H$ with a path from $u$ to $v$ in $D$ such that these paths are pairwise…

Combinatorics · Mathematics 2025-12-18 Jia Zhou , Jin Yan

We study asymptotic percolation as $N\to \infty$ in an infinite random graph ${\cal G}_N$ embedded in the hierarchical group of order $N$, with connection probabilities depending on an ultrametric distance between vertices. ${\cal G}_N$ is…

Probability · Mathematics 2007-05-23 D. A. Dawson , L. G. Gorostiza

For an $n$-vertex graph $G$, let $h(G)$ denote the smallest size of a subset of $V(G)$ such that it intersects every maximum independent set of $G$. A conjecture posed by Bollob\'{a}s, Erd\H{o}s and Tuza in early 90s remains widely open,…

Combinatorics · Mathematics 2024-12-06 Xinbu Cheng , Xinqi Huang , Mingyuan Rong , Zixiang Xu

It is a classical result that a random permutation of $n$ elements has, on average, about $\log n$ cycles. We generalise this fact to all directed $d$-regular graphs on $n$ vertices by showing that, on average, a random cycle-factor of such…

Combinatorics · Mathematics 2025-08-26 Micha Christoph , Nemanja Draganić , António Girão , Eoin Hurley , Lukas Michel , Alp Müyesser

We consider a random geometric hypergraph model based on an underlying bipartite graph. Nodes and hyperedges are sampled uniformly in a domain, and a node is assigned to those hyperedges that lie with a certain radius. From a modelling…

Probability · Mathematics 2023-09-19 Henry-Louis de Kergorlay , Desmond J. Higham

Let $d \geq 3$ be a fixed integer. We give an asympotic formula for the expected number of spanning trees in a uniformly random $d$-regular graph with $n$ vertices. (The asymptotics are as $n\to\infty$, restricted to even $n$ if $d$ is…

Combinatorics · Mathematics 2024-05-31 Catherine Greenhill , Matthew Kwan , David Wind

In this paper, we determine the bound of the valency of the odd circulant graph which guarantees to be a Ramanujan graph for each fixed number of vertices. In almost of the cases, the bound coincides with the trivial bound, which comes from…

Number Theory · Mathematics 2015-03-16 Miki Hirano , Kohei Katata , Yoshinori Yamasaki

Let $G$ be a graph on $n$ vertices and let $k$ be a fixed positive integer. We denote by $\mathcal G_{\text{$k$-out}}(G)$ the probability space consisting of subgraphs of $G$ where each vertex $v\in V(G)$ randomly picks $k$ neighbors from…

Combinatorics · Mathematics 2014-10-09 Asaf Ferber , Gal Kronenberg , Frank Mousset , Clara Shikhelman

One of the most famous results in the theory of random graphs establishes that the threshold for Hamiltonicity in the Erdos-Renyi random graph G_{n,p} is around p ~ (log n + log log n) / n. Much research has been done to extend this to…

Combinatorics · Mathematics 2011-01-04 Alan Frieze , Po-Shen Loh

We study the recently introduced boolean-width of graphs. Our structural results are as follows. Firstly, we show that almost surely the boolean-width of a random graph on $n$ vertices is $O(\log^2 n)$, and it is easy to find the…

Combinatorics · Mathematics 2009-08-20 Y. Rabinovich , J. A. Telle

We study the distribution of the set of copies of some given graph $H$ in the random graph $G(n,p)$, focusing on the case when $H = K_r$. Our main results capture the 'leading term' in the difference between this distribution and the…

Combinatorics · Mathematics 2025-04-02 Robert Morris , Oliver Riordan

We develop a thorough analytical study of the $O(1/N)$ correction to the spectrum of regular random graphs with $N \rightarrow \infty$ nodes. The finite size fluctuations of the resolvent are given in terms of a weighted series over the…

Disordered Systems and Neural Networks · Physics 2014-11-18 Fernando L. Metz , Giorgio Parisi , Luca Leuzzi

For a given permutation $\pi_n$ in $S_n$, a random permutation graph is formed by including an edge between two vertices $i$ and $j$ if and only if $(i - j) (\pi_n(i) - \pi_n (j)) < 0$. In this paper, we study various statistics of random…

Combinatorics · Mathematics 2021-08-02 Oğuz Gürerk , Ümit Işlak , Mehmet Akif Yıldız

We introduce a new random mapping model, $T_n^{\hat D}$, which maps the set $\{1,2,...,n\}$ into itself.The random mapping $T_n^{\hat D}$ is constructed using a collection of exchangeable random variables $\hat{D}_1, ....,\hat{D}_n$ which…

Probability · Mathematics 2007-05-23 Jennie C. Hansen , Jerzy Jaworski