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A subset $S$ of initially infected vertices of a graph $G$ is called forcing if we can infect the entire graph by iteratively applying the following process. At each step, any infected vertex which has a unique uninfected neighbour, infects…

Combinatorics · Mathematics 2017-06-06 Thomas Kalinowski , Nina Kamčev , Benny Sudakov

The rank of a graph is defined to be the rank of its adjacency matrix. A graph is called reduced if it has no isolated vertices and no two vertices with the same set of neighbors. A reduced graph $G$ is said to be maximal if any reduced…

Combinatorics · Mathematics 2020-10-09 H. Esmailian , E. Ghorbani , S. Hossein Ghorban , G. B. Khosrovshahi

Let $G$ be a graph on $n$ vertices. For $i\in \{0,1\}$ and a connected graph $G$, a spanning forest $F$ of $G$ is called an $i$-perfect forest if every tree in $F$ is an induced subgraph of $G$ and exactly $i$ vertices of $F$ have even…

Combinatorics · Mathematics 2021-07-09 Gregory Gutin , Anders Yeo

Given a graph $G$ and a real number $0\le p\le 1$, we define the random set $B_p(G)\subset V(G)$ by including each vertex independently and with probability $p$. We investigate the probability that the random set $B_p(G)$ is a zero forcing…

Combinatorics · Mathematics 2022-08-30 Bryan Curtis , Luyining Gan , Jamie Haddock , Rachel Lawrence , Sam Spiro

In this paper, we study minimal (with respect to inclusion) zero forcing sets. We first investigate when a graph can have polynomially or exponentially many distinct minimal zero forcing sets. We also study the maximum size of a minimal…

Combinatorics · Mathematics 2022-04-18 Boris Brimkov , Joshua Carlson

The positive zero forcing number of a graph is a graph parameter that arises from a non-traditional type of graph colouring, and is related to a more conventional version of zero forcing. We establish a relation between the zero forcing and…

Combinatorics · Mathematics 2014-07-28 Shaun Fallat , Karen Meagher , Boting Yang

Let $G$ be a simple, finite, and undirected graph with vertices each given an initial coloring of either blue or white. Zero forcing on graph $G$ is an iterative process of forcing its white vertices to become blue after a finite…

Combinatorics · Mathematics 2022-02-11 Ma. Nerissa M. Abara , Prince Allan B. Pelayo

Zero forcing is an iterative graph coloring process studied for its wide array of applications. In this process, the vertices of the graph are initially designated as blue or white, and a zero forcing set is a set of initially blue vertices…

Combinatorics · Mathematics 2026-03-23 Asher Brown , Mark Hunnell , Za'Kiyah Toomer-Sanders , Sarah Weber

In zero forcing, the focus is typically on finding the minimum cardinality of any zero forcing set in the graph; however, the number of cardinalities between $0$ and the number of vertices in the graph for which there are both zero forcing…

Combinatorics · Mathematics 2023-09-13 Bonnie Jacob

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

Given a graph G=(V, E), a vertex is said to ve-dominate an edge if it is either incident with the edge or adjacent to one of its endpoints. A set of vertices is a ve-dominating set if it ve-dominates every edge of the graph. We introduce…

Combinatorics · Mathematics 2025-12-16 Yasemin Büyükçolak

Let $G$ be a simple and finite graph without isolated vertices. In this paper we study forcing sets (zero forcing sets) which induce a subgraph of $G$ without isolated vertices. Such a set is called a total forcing set, introduced and first…

Combinatorics · Mathematics 2017-02-28 Randy Davila , Michael A. Henning

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

The (disjoint) fort number and fractional zero forcing number are introduced and related to existing parameters including the (standard) zero forcing number. The fort hypergraph is introduced and hypergraph results on transversals and…

We consider bounds on maximum nullity of a graph via transversal numbers of compatible collections of forts. Results include generalizations of theorems from symmetric to combinatorially symmetric matrices, special bases of matrix…

Combinatorics · Mathematics 2024-07-08 Veronika Furst , John Hutchens , Lon Mitchell , Yaqi Zhang

A connected graph is called fragile if it contains an independent vertex cut. In 2002 Chen and Yu proved that every connected graph of order $n$ and size at most $2n-4$ is fragile, and in 2013 Le and Pfender characterized the non-fragile…

Combinatorics · Mathematics 2024-12-06 Kun Cheng , Yurui Tang , Xingzhi Zhan

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

In this paper, controllability of systems defined on graphs is discussed. We consider the problem of controllability of the network for a family of matrices carrying the structure of an underlying directed graph. A one-to-one correspondence…

Systems and Control · Computer Science 2014-03-20 Nima Monshizadeh , Shuo Zhang , Kanat Camlibel

Zero forcing in graphs is a coloring process where a colored vertex can force its unique uncolored neighbor to be colored. A zero forcing set is a set of initially colored vertices capable of eventually coloring all vertices of the graph.…

Combinatorics · Mathematics 2024-05-03 Krishna Menon , Anurag Singh

Zero forcing is an iterative graph coloring process where at each discrete time step, a colored vertex with a single uncolored neighbor forces that neighbor to become colored. The zero forcing number of a graph is the cardinality of the…

Discrete Mathematics · Computer Science 2017-02-06 Boris Brimkov , Caleb C. Fast , Illya V. Hicks