English
Related papers

Related papers: The zero blocking numbers of grid graphs

200 papers

An $r$-fold analogue of the positive semidefinite zero forcing process that is carried out on the $r$-blowup of a graph is introduced and used to define the fractional positive semidefinite forcing number. Properties of the graph blowup…

Combinatorics · Mathematics 2016-08-23 Leslie Hogben , Kevin F. Palmowski , David E. Roberson , Michael Young

The sorting number of a graph with $n$ vertices is the minimum depth of a sorting network with $n$ inputs and outputs that uses only the edges of the graph to perform comparisons. Many known results on sorting networks can be stated in…

Data Structures and Algorithms · Computer Science 2022-03-22 Indranil Banerjee , Dana Richards , Igor Shinkar

An isolating set in a graph is a set $X$ of vertices such that every edge of the graph is incident with a vertex of $X$ or its neighborhood. The isolation number of a graph, or equivalently the vertex-edge domination number, is the minimum…

Combinatorics · Mathematics 2024-05-22 Geoffrey Boyer , Wayne Goddard

The Zero divisor Graph of a commutative ring $R$, denoted by $\Gamma[R]$, is a graph whose vertices are non-zero zero divisors of $R$ and two vertices are adjacent if their product is zero. In this paper we derive the Vertex and Edge…

Rings and Algebras · Mathematics 2018-07-11 B. Surendranath Reddy , Rupali. S. Jain , N. Laxmikanth

The zero forcing number is a graph invariant introduced to study the minimum rank of the graph. In 2008, Aazami proved the NP-hardness of computing the zero forcing number of a simple undirected graph. We complete this NP-hardness result by…

Discrete Mathematics · Computer Science 2015-06-09 Maguy Trefois , Jean-Charles Delvenne

Given a graph $G$, an {\em obstacle representation} of $G$ is a set of points in the plane representing the vertices of $G$, together with a set of connected obstacles such that two vertices of $G$ are joined by an edge if and only if the…

Combinatorics · Mathematics 2011-03-15 Padmini Mukkamala , János Pach , Dömötör Pálvölgyi

In this paper we introduce a class of regular bipartite graphs whose biadjacency matrices are circulant matrices and we describe some of their properties. Notably, we compute upper and lower bounds for the zero forcing number for such a…

Combinatorics · Mathematics 2010-11-29 Seth A. Meyer

Let $S$ be a set of vertices of a graph $G$. Let $cl(S)$ be the set of vertices built from $S$, by iteratively applying the following propagation rule: if a vertex and all but exactly one of its neighbors are in $cl(S)$, then the remaining…

Combinatorics · Mathematics 2019-08-09 Najibeh Shahbaznejad , Ignacio M. Pelayo , Adel P. Kazemi

Vertex leaky forcing was recently introduced as a new variation of zero forcing in order to show how vertex leaks can disrupt the zero forcing process in a graph. An edge leak is an edge that is not allowed to be forced across during the…

Combinatorics · Mathematics 2020-09-16 Joseph S. Alameda , Juergen Kritschgau , Michael Young

A dynamic coloring of the vertices of a graph $G$ starts with an initial subset $S$ of colored vertices, with all remaining vertices being non-colored. At each discrete time interval, a colored vertex with exactly one non-colored neighbor…

Combinatorics · Mathematics 2018-01-17 Randy Davila , Michael Henning

Let $G=(V,E)$ be a simple connected graph. A perfect matching (or Kekul\'e structure in chemical literature) of $G$ is a set of disjoint edges which covers all vertices of $G$. The anti-forcing number of $G$ is the smallest number of edges…

Combinatorics · Mathematics 2018-07-24 Neda Soltani , Saeid Alikhani

Several researchers have recently explored various graph parameters that can or cannot be characterized by the spectrum of a matrix associated with a graph. In this paper we show that several NP-hard zero forcing numbers are not…

Combinatorics · Mathematics 2022-04-25 Aida Abiad , Boris Brimkov , Jane Breen , Thomas R. Cameron , Himanshu Gupta , Ralihe R. Villagrán

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

We introduce a new variant of zero forcing - signed zero forcing. The classical zero forcing number provides an upper bound on the maximum nullity of a matrix with a given graph (i.e. zero-nonzero pattern). Our new variant provides an…

Combinatorics · Mathematics 2013-07-09 Felix Goldberg , Abraham Berman

For a given number of colors, $s$, the guessing number of a graph is the (base $s$) logarithm of the cardinality of the largest family of colorings of the vertex set of the graph such that the color of each vertex can be determined from the…

Combinatorics · Mathematics 2020-09-11 Jo Martin , Puck Rombach

Probabilistic zero forcing is a graph coloring process in which blue vertices "infect" (color blue) white vertices with a probability proportional to the number of neighboring blue vertices. We introduce reversion probabilistic zero forcing…

Combinatorics · Mathematics 2024-04-24 Zachary Brennan

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 an undirected simple graph, a subset of the vertices of the graph is a {\em dominating set} if every vertex not in the subset is adjacent to at least one vertex in the subset. A subset of the vertices of the graph is a {\em connected…

Combinatorics · Mathematics 2021-09-30 Masahisa Goto , Koji M. Kobayashi

Zero forcing number has recently become an interesting graph parameter studied in its own right since its introduction by the "AIM Minimum Rank -- Special Graphs Work Group", whereas metric dimension is a well-known graph parameter. We…

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

The total domination number of a graph $G$ without isolated vertices is the minimum number of vertices that dominate all vertices in $G$. The total bondage number $b_t(G)$ of $G$ is the minimum number of edges whose removal enlarges the…

Combinatorics · Mathematics 2011-09-20 Fu-Tao Hu , You Lu , Jun-Ming Xu
‹ Prev 1 3 4 5 6 7 10 Next ›