English
Related papers

Related papers: On the $Z_q$-forcing number: computational approac…

200 papers

In 2018, forts were defined as non-empty subsets of vertices in a graph where no vertex outside the set has exactly one neighbor in the set. Forts have since been used to characterize zero forcing sets, model zero forcing as an integer…

Combinatorics · Mathematics 2025-07-16 Boris Brimkov , Thomas R. Cameron , Owen Grubbs

The zero forcing number of a graph $G$, denoted by $Z(G)$, is the minimum cardinality of a set $S$ of black vertices (where vertices in $V(G)\setminus S$ are colored white) such that $V(G)$ is turned black after finitely many applications…

Combinatorics · Mathematics 2017-02-20 I. Javaid , I. Irshad , M. Batool , Z. Raza

Given a graph $G$, one may ask: "What sets of eigenvalues are possible over all weighted adjacency matrices of $G$?" (The weight of an edge is positive or negative, while the diagonal entries can be any real numbers.) This is known as the…

Combinatorics · Mathematics 2021-04-14 Franklin H. j. Kenter , Jephian C. -H. Lin

Several concepts that model processes of spreading (of information, disease, objects, etc.) in graphs or networks have been studied. In many contexts, we assume that some vertices of a graph $G$ are contaminated initially, before the…

Combinatorics · Mathematics 2023-10-03 Boštjan Brešar , Tanja Dravec , Aysel Erey , Jaka Hedžet

Motivated by a conjecture from the automated conjecturing program TxGraffiti, in this paper the relationship between the zero forcing number, $Z(G)$, and the vertex independence number, $\alpha(G)$, of cubic and subcubic graphs is explored.…

Combinatorics · Mathematics 2024-11-04 Houston Schuerger , Nathan Warnberg , Michael Young

We prove that the \emph{standard zero forcing number} $Z(G)$ and the \emph{positive semidefinite zero forcing number} $Z_+(G)$ are equal for all claw-free graphs $G$. This result resolves a conjecture proposed by the computer program…

Combinatorics · Mathematics 2024-12-19 Randy Davila , Houston Schuerger , Ben Small

Let $D$ be a simple digraph (directed graph) with vertex set $V(D)$ and arc set $A(D)$ where $n=|V(D)|$, and each arc is an ordered pair of distinct vertices. If $(v,u) \in A(D)$, then $u$ is considered an \emph{out-neighbor} of $v$ in $D$.…

Combinatorics · Mathematics 2020-07-31 Alyssa Adams , Bonnie Jacob

Parity games are games that are played on directed graphs whose vertices are labeled by natural numbers, called priorities. The players push a token along the edges of the digraph. The winner is determined by the parity of the greatest…

Computer Science and Game Theory · Computer Science 2015-03-20 Christoph Dittmann , Stephan Kreutzer , Alexandru I. Tomescu

We introduce a family of forcing notions that are helpful in showing that certain graphs do not have countable colourings of (additive) Borel class alpha. We construct graphs that are ''weakly minimal'' for such colourings.

General Topology · Mathematics 2026-04-08 Noam Greenberg , Dominique Lecomte , Dan Turetsky , Miroslav Zelen

Given a graph $G=(V, E)$, the problem of Graph Burning is to find a sequence of nodes from $V$, called a burning sequence, to burn the whole graph. This is a discrete-step process, and at each step, an unburned vertex is selected as an…

Data Structures and Algorithms · Computer Science 2023-07-18 Rahul Kumar Gautam , Anjeneya Swami Kare , S. Durga Bhavani

An approximation algorithm for a constraint satisfaction problem is called robust if it outputs an assignment satisfying a $(1 - f(\epsilon))$-fraction of the constraints on any $(1-\epsilon)$-satisfiable instance, where the loss function…

Data Structures and Algorithms · Computer Science 2022-11-09 Antoine Méot , Arnaud de Mesmay , Moritz Mühlenthaler , Alantha Newman

The \emph{zero forcing number}, $Z(G)$, of a graph $G$ is the minimum cardinality of a set $S$ of black vertices (whereas vertices in $V(G)-S$ are colored white) such that $V(G)$ is turned black after finitely many applications of "the…

Combinatorics · Mathematics 2014-12-11 Cong X. Kang , Eunjeong Yi

Recently, there have been found new relations between the zero forcing number and the minimum rank of a graph with the algebraic co-rank. We continue on this direction by giving a characterization of the graphs with real algebraic co-rank…

Combinatorics · Mathematics 2020-05-06 Carlos A. Alfaro

In this paper, we initiate the study of the inverse eigenvalue problem for probe graphs. A probe graph is a graph whose vertices are partitioned into probe vertices and non-probe vertices such that the non-probe vertices form an independent…

Combinatorics · Mathematics 2024-03-01 Emelie Curl , Jürgen Kritschgau , Carolyn Reinhart , Hein van der Holst

This paper considers a class of two-player zero-sum games on directed graphs whose vertices are equipped with random payoffs of bounded support known by both players. Starting from a fixed vertex, players take turns to move a token along…

Optimization and Control · Mathematics 2024-01-30 Luc Attia , Lyuben Lichev , Dieter Mitsche , Raimundo Saona , Bruno Ziliotto

The maximum oriented $k$-forcing number of a simple graph $G$, written $\MOF_k(G)$, is the maximum directed $k$-forcing number among all orientations of $G$. This invariant was recently introduced by Caro, Davila and Pepper in…

Combinatorics · Mathematics 2017-09-25 Yair Caro , Ryan Pepper

We investigate the zero-forcing number for triangle-free graphs. We improve upon the trivial bound, $\delta \le Z(G)$ where $\delta$ is the minimum degree, in the triangle-free case. In particular, we show that $2 \delta - 2 \le Z(G)$ for…

Combinatorics · Mathematics 2014-06-13 Randy Davila , Franklin Kenter

This paper proves a conjecture generated by the artificial intelligence conjecturing program called \emph{TxGraffiti}. More specifically, we show that if $G$ is a connected, cubic, and claw-free graph, then $Z(G) \le \gamma(G) + 2$, where…

Combinatorics · Mathematics 2024-11-20 Randy R. Davila

We introduce ZykovColor, a novel SAT-based algorithm to solve the graph coloring problem working on top of an encoding that mimics the Zykov tree. Our method is based on an approach of H\'ebrard and Katsirelos (2020) that employs a…

Discrete Mathematics · Computer Science 2025-10-15 Timo Brand , Daniel Faber , Stephan Held , Petra Mutzel

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