English
Related papers

Related papers: Linear-sized independent sets in random cographs a…

200 papers

We use an entropy based method to study two graph maximization problems. We upper bound the number of matchings of fixed size $\ell$ in a $d$-regular graph on $N$ vertices. For $\frac{2\ell}{N}$ bounded away from 0 and 1, the logarithm of…

Combinatorics · Mathematics 2012-06-15 Teena Carroll , David Galvin , Prasad Tetali

It has been conjectured by W. Chen that the distribution of the length of the longest increasing subsequence in a uniformly random permutation is log-concave. We propose a stronger version of this conjecture which involves the Kronecker…

Combinatorics · Mathematics 2020-06-24 Jonathan Novak , Brendon Rhoades

We consider large uniform labeled random graphs in different classes with prescribed decorations in their modular decomposition. Our main result is the estimation of the number of copies of every graph as an induced subgraph. As a…

Combinatorics · Mathematics 2023-10-25 Théo Lenoir

Permutations of correlated sequences of random variables appear naturally in a variety of applications such as graph matching and asynchronous communications. In this paper, the asymptotic statistical behavior of such permuted sequences is…

Information Theory · Computer Science 2020-01-22 Farhad Shirani , Siddharth Garg , Elza Erkip

The purpose of this note is to point out that the theory of expander graphs leads to an interesting test whether $n$ real numbers $x_1, \dots, x_n$ could be $n$ independent samples of a random variable. To any distinct, real numbers $x_1,…

Statistics Theory · Mathematics 2020-08-05 Stefan Steinerberger

The independence number of a sparse random graph G(n,m) of average degree d=2m/n is well-known to be \alpha(G(n,m))~2n ln(d)/d with high probability. Moreover, a trivial greedy algorithm w.h.p. finds an independent set of size (1+o(1)) n…

Discrete Mathematics · Computer Science 2017-11-29 Amin Coja-Oghlan , Charilaos Efthymiou

The size of a largest independent set of vertices in a given graph $G$ is denoted by $\alpha(G)$ and is called its independence number (or stability number). Given a graph $G$ and an integer $K,$ it is NP-complete to decide whether…

Combinatorics · Mathematics 2017-09-11 Ingo Schiermeyer

Let $i_t(G)$ denote the number of independent sets of size $t$ in a graph $G$. Levit and Mandrescu have conjectured that for all bipartite $G$ the sequence $(i_t(G))_{t \geq 0}$ (the {\em independent set sequence} of $G$) is unimodal. We…

Combinatorics · Mathematics 2012-06-15 David Galvin

We consider classes of pseudo-random graphs on $n$ vertices for which the degree of every vertex and the co-degree between every pair of vertices are in the intervals $(np - Cn^\delta,np+Cn^\delta)$ and $(np^2- C n^\delta, np^2 +C…

Probability · Mathematics 2016-10-13 Anirban Basak , Shankar Bhamidi , Suman Chakraborty , Andrew Nobel

By Brook's Theorem, every n-vertex graph of maximum degree at most Delta >= 3 and clique number at most Delta is Delta-colorable, and thus it has an independent set of size at least n/Delta. We give an approximate characterization of graphs…

Discrete Mathematics · Computer Science 2019-11-05 Zdenek Dvorak , Bernard Lidicky

An ordered $r$-uniform matching of size $n$ is a collection of $n$ pairwise disjoint $r$-subsets of a linearly ordered set of $rn$ vertices. For $n=2$, such a matching is called an $r$-pattern, as it represents one of $\tfrac12\binom{2r}r$…

Combinatorics · Mathematics 2026-02-09 Andrzej Dudek , Jarosław Grytczuk , Jakub Przybyło , Andrzej Ruciński

It is shown in this note that approximating the number of independent sets in a $k$-uniform linear hypergraph with maximum degree at most $\Delta$ is NP-hard if $\Delta\geq 5\cdot 2^{k-1}+1$. This confirms that for the relevant sampling and…

Computational Complexity · Computer Science 2023-09-29 Guoliang Qiu , Jiaheng Wang

It is conjectured by Frankl and F\"uredi that the $r$-uniform hypergraph with $m$ edges formed by taking the first $m$ sets in the colex ordering of ${\mathbb N}^{(r)}$ has the largest Lagrangian of all $r$-uniform hypergraphs with $m$…

Combinatorics · Mathematics 2014-05-13 Qingsong Tang , Xiaojun Lu , Xiangde Zhang , Cheng Zhao

The well-known Erd\H{o}s-Hajnal conjecture states that for any graph $F$, there exists $\epsilon>0$ such that every $n$-vertex graph $G$ that contains no induced copy of $F$ has a homogeneous set of size at least $n^{\epsilon}$. We consider…

Combinatorics · Mathematics 2023-05-03 Maria Axenovich , Domagoj Bradač , Lior Gishboliner , Dhruv Mubayi , Lea Weber

Amongst $d$-regular $r$-uniform hypergraphs on $n$ vertices, which ones have the largest number of independent sets? While the analogous problem for graphs (originally raised by Granville) is now well-understood, it is not even clear what…

Combinatorics · Mathematics 2020-02-25 Jozsef Balogh , Bela Bollobas , Bhargav Narayanan

Let $G$ be a graph $G$ whose largest independent set has size $m$. A permutation $\pi$ of $\{1, \ldots, m\}$ is an {\em independent set permutation} of $G$ if $$ a_{\pi(1)}(G) \leq a_{\pi(2)}(G) \leq \cdots \leq a_{\pi(m)}(G) $$ where…

Combinatorics · Mathematics 2021-07-14 Taylor Ball , David Galvin , Catherine Hyry , Kyle Weingartner

There has been interest recently in maximizing the number of independent sets in graphs. For example, the Kahn-Zhao theorem gives an upper bound on the number of independent sets in a $d$-regular graph. Similarly, it is a corollary of the…

Combinatorics · Mathematics 2019-03-21 Lauren Keough , A. J. Radcliffe

In this note, we consider the problem of finding a step-by-step transformation between two longest increasing subsequences in a sequence, namely Longest Increasing Subsequence Reconfiguration. We give a polynomial-time algorithm for…

Data Structures and Algorithms · Computer Science 2023-10-03 Yuuki Aoike , Masashi Kiyomi , Yasuaki Kobayashi , Yota Otachi

Computing the maximum size of an independent set in a graph is a famously hard combinatorial problem that has been well-studied for various classes of graphs. When it comes to random graphs, only the classical Erd\H{o}s-R\'enyi-Gilbert…

Combinatorics · Mathematics 2024-07-17 Akshay Gupte , Yiran Zhu

An $n$-vertex, $d$-regular graph can have at most $2^{n/2+o_d(n)}$ independent sets. In this paper we address what happens with this upper bound when we impose the further condition that the graph has independence number at most $\alpha$.…

Combinatorics · Mathematics 2024-10-29 David Galvin , Phillip Marmorino