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We give nearly optimal bounds on the sample complexity of $(\widetilde{\Omega}(\epsilon),\epsilon)$-tolerant testing the $\rho$-independent set property in the dense graph setting. In particular, we give an algorithm that inspects a random…

Data Structures and Algorithms · Computer Science 2025-03-28 Cameron Seth

Recently, settling a question of Erd\H{o}s, Balogh and Pet\v{r}\'{i}\v{c}kov\'{a} showed that there are at most $2^{n^2/8+o(n^2)}$ $n$-vertex maximal triangle-free graphs, matching the previously known lower bound. Here we characterize the…

Combinatorics · Mathematics 2016-08-07 József Balogh , Hong Liu , Šárka Petříčková , Maryam Sharifzadeh

For a graph $G$, a subset $S$ of $V(G)$ is a {\it hop dominating set} of $G$ if every vertex not in $S$ has a $2$-step neighbor in $S$. The {\it hop domination number}, $\gamma_h(G)$, of $G$ is the minimum cardinality of a hop dominating…

Combinatorics · Mathematics 2025-03-07 Shinya Fujita , Boram Park

Given a graphical degree sequence ${\bf d}=(d_1,\ldots, d_n)$, let $G(n, {\bf d})$ denote a uniformly random graph on vertex set $[n]$ where vertex $ i$ has degree $d_i$ for every $1\le i\le n$. We give upper and lower bounds on the joint…

Combinatorics · Mathematics 2025-05-28 Pu Gao , Yuval Ohapkin

Given a finite, simple graph $G$, the independent bondage number of $G$ is the minimum size of an edge set such that its deletion results in a graph with strictly larger independent domination number than that of $G$. While the bondage…

Combinatorics · Mathematics 2025-10-15 E. G. K. M. Gamlath , Andrew Pham , Bing Wei

A set $S\subseteq V$ of a graph $G=(V,E)$ is a dominating set if each vertex has a neighbor in $S$ or belongs to $S$. Dominating Set is the problem of deciding, given a graph $G$ and an integer $k\geq 1$, if $G$ has a dominating set of size…

Combinatorics · Mathematics 2023-04-20 Valentin Bouquet , François Delbot , Christophe Picouleau , Stéphane Rovedakis

We study the zero sets of the independence polynomial on recursive sequences of graphs. We prove that for a maximally independent starting graph and a stable and expanding recursion algorithm, the zeros of the independence polynomial are…

Dynamical Systems · Mathematics 2024-11-25 Mikhail Hlushchanka , Han Peters

We consider the number of independent sets in hypergraphs, which allows us to define the independence density of countable hypergraphs. Hypergraph independence densities include a broad family of densities over graphs and relational…

Combinatorics · Mathematics 2013-08-14 Anthony Bonato , Jason Brown , Dieter Mitsche , Pawel Pralat

The following natural problem was raised independently by Erd\H{o}s-Hajnal and Linial-Rabinovich in the late 80's. How large must the independence number $\alpha(G)$ of a graph $G$ be whose every $m$ vertices contain an independent set of…

Combinatorics · Mathematics 2023-01-18 Matija Bucić , Benny Sudakov

For $r\geq 1$, the $r$-independence complex of a graph $G$, denoted Ind$_r(G)$, is a simplicial complex whose faces are subsets $A \subseteq V(G)$ such that each component of the induced subgraph $G[A]$ has at most $r$ vertices. In this…

Combinatorics · Mathematics 2020-01-22 Priyavrat Deshpande , Samir Shukla , Anurag Singh

The independence polynomial of a graph is the generating polynomial for the number of independent sets of each size and its roots are called independence roots. We bound the maximum modulus, $\mbox{maxmod}(n)$, of an independence root over…

Combinatorics · Mathematics 2018-12-27 Jason I. Brown , Ben Cameron

Getting inspired by the famous no-three-in-line problem and by the general position subset selection problem from discrete geometry, the same is introduced into graph theory as follows. A set $S$ of vertices in a graph $G$ is a general…

Combinatorics · Mathematics 2020-04-10 Elias John Thomas , Ullas Chandran S. V.

Given a positive integer $r$ and a graph $G$ with degree sequence $d_1,\dots,d_n$, we define $e_r(G)=\sum_{i=1}^n d_i^r$. We let $\mathrm{ex}_r(n,F)$ be the largest value of $e_r(G)$ if $G$ is an $n$-vertex $F$-free graph. We show that if…

Combinatorics · Mathematics 2025-03-12 Dániel Gerbner

We consider Colouring on graphs that are $H$-subgraph-free for some fixed graph $H$, which are graphs that do not contain $H$ as a subgraph. To classify the complexity of Colouring on $H$-subgraph-free graphs for connected $H$, it remains…

Combinatorics · Mathematics 2026-02-23 Tala Eagling-Vose , Jorik Jooken , Felicia Lucke , Barnaby Martin , Daniël Paulusma

A set S is independent in a graph G if no two vertices from S are adjacent. By core(G) we mean the intersection of all maximum independent sets. The independence number alpha(G) is the cardinality of a maximum independent set, while mu(G)…

Discrete Mathematics · Computer Science 2011-02-24 Vadim E. Levit , Eugen Mandrescu

Let $G$ be a simple graph with maximum degree $\Delta(G)$ and chromatic index $\chi'(G)$. A classic result of Vizing indicates that either $\chi'(G )=\Delta(G)$ or $\chi'(G )=\Delta(G)+1$. The graph $G$ is called $\Delta$-critical if $G$ is…

Combinatorics · Mathematics 2018-05-17 Yan Cao , Guantao Chen , Guangming Jing , Songling Shan

A graph is perfectly divisible if for each of its induced subgraph $H$, $V(H)$ can be partitioned into $A$ and $B$ such that $H[A]$ is perfect and $\omega(H[B]) < \omega(H)$, and a graph $G$ is perfectly weight divisible if for every…

Combinatorics · Mathematics 2026-03-06 Qiming Hu , Baogang Xu , Miaoxia Zhuang

A connected graph $G$ with a perfect matching is said to be $k$-extendable for integers $k$, $1 \leq k\leq \frac{|V(G)|}{2}-1$, if any matching in $G$ of size $k$ is contained in a perfect matching of $G$. A $k$-extendable graph is minimal…

Combinatorics · Mathematics 2025-10-07 Jing Guo , Fuliang Lu , Heping Zhang

Let $G$ be a graph of order $n$ and let $k\in\{1,\ldots,n-1\}$. The $k$-token graph $F_k(G)$ of $G$, is the graph whose vertices are the $k$-subsets of $V(G)$, where two vertices are adjacent in $F_k(G)$ whenever their symmetric difference…

Combinatorics · Mathematics 2023-12-01 Hernan de Alba , Walter Carballosa , Jesús Leaños , Luis Manuel Rivera

We show that every (sub)cubic n-vertex graph with sufficiently large girth has fractional chromatic number at most 2.2978 which implies that it contains an independent set of size at least 0.4352n. Our bound on the independence number is…

Combinatorics · Mathematics 2010-10-19 Frantisek Kardos , Daniel Kral , Jan Volec