English
Related papers

Related papers: Solution to a $3$-path isolation problem for subcu…

200 papers

The $3$-path isolation number of a connected $n$-vertex graph $G$, denoted by $\iota(G,P_3)$, is the size of a smallest subset $D$ of the vertex set of $G$ such that the closed neighbourhood $N[D]$ of $D$ in $G$ intersects each $3$-vertex…

Combinatorics · Mathematics 2025-06-25 Karl Bartolo , Peter Borg , Dayle Scicluna

For a connected $n$-vertex graph $G$ and a set $\mathcal{F}$ of graphs, let $\iota(G,\mathcal{F})$ denote the size of a smallest set $D$ of vertices of $G$ such that the graph obtained from $G$ by deleting the closed neighbourhood of $D$…

Combinatorics · Mathematics 2021-10-11 Peter Borg

Given a set $\mathcal{F}$ of graphs, we call a copy of a graph in $\mathcal{F}$ an $\mathcal{F}$-graph. The $\mathcal{F}$-isolation number of a graph $G$, denoted by $\iota(G, \mathcal{F})$, is the size of a smallest set $D$ of vertices of…

Combinatorics · Mathematics 2025-10-10 Peter Borg , Dayle Scicluna

Let $G$ be a graph. A subset $D \subseteq V(G)$ is called a 1-isolating set of $G$ if $\Delta(G-N[D]) \leq 1$, that is, $G-N[D]$ consists of isolated edges and isolated vertices only. The $1$-isolation number of $G$, denoted by…

Combinatorics · Mathematics 2023-08-02 Yirui Huang , Gang Zhang , Xian'an Jin

Given a set $\mathcal{F}$ of graphs, we call a copy of a graph in $\mathcal{F}$ an $\mathcal{F}$-graph. The $\mathcal{F}$-isolation number of a graph $G$, denoted by $\iota(G,\mathcal{F})$, is the size of a smallest subset $D$ of the vertex…

Combinatorics · Mathematics 2024-08-21 Karl Bartolo , Peter Borg , Dayle Scicluna

A set $D$ of vertices of a graph $G$ is isolating if the set of vertices not in $D$ or with no neighbor in $D$ is independent. The isolation number of $G$, denoted by $\iota (G)$, is the minimum cardinality of an isolating set of $G$. It is…

Combinatorics · Mathematics 2024-05-09 Magdalena Lemanska , Mercè Mora , María José Souto-Salorio

For any graph $G$, let $\iota_{\rm c}(G)$ denote the size of a smallest set $D$ of vertices of $G$ such that the graph obtained from $G$ by deleting the closed neighbourhood of $D$ contains no cycle. We prove that if $G$ is a connected…

Combinatorics · Mathematics 2018-12-24 Peter Borg

Let $C_k$ be the cycle of length $k$. For any graph $G$, a subset $D \subseteq V(G)$ is a $C_k$-isolating set of $G$ if the graph obtained from $G$ by deleting the closed neighbourhood of $D$ contains no $C_k$ as a subgraph. The…

Combinatorics · Mathematics 2023-10-27 Xiaohua Wei , Gang Zhang , Biao Zhao

A copy of a graph $F$ is called an $F$-copy. For any graph $G$, the $F$-isolation number of $G$, denoted by $\iota(G,F)$, is the size of a smallest subset $D$ of the vertex set of $G$ such that the closed neighbourhood $N[D]$ of $D$ in $G$…

Combinatorics · Mathematics 2025-06-12 Peter Borg , Alastair Farrugia

The isolation number of a graph $G$ (also called the vertex-edge domination number of $G$), denoted by $\iota(G)$, is the size of a smallest subset $D$ of the vertex set $V(G)$ of $G$ such that $G-N[D]$ (the graph obtained by deleting the…

Combinatorics · Mathematics 2025-02-17 Peter Borg , Magdalena Lemańska , Mercè Mora , María José Souto-Salorio

This paper introduces the notion of an $(\iota,q)$-critical graph. The isolation number of a graph $G$, denoted by $\iota(G)$ and also known as the vertex-edge domination number of $G$, is the size of a smallest subset $D$ of the vertex set…

Combinatorics · Mathematics 2026-03-24 Karl Bartolo , Peter Borg , Magda Dettlaff , Magdalena Lemańska , Paweł Żyliński

Given a set $\mathcal{F}$ of graphs, we call a copy of a graph in $\mathcal{F}$ an $\mathcal{F}$-graph. The $\mathcal{F}$-isolation number of a graph $G$, denoted by $\iota(G,\mathcal{F})$, is the size of a smallest set $D$ of vertices of…

Combinatorics · Mathematics 2025-08-21 Peter Borg

An isolating set in a graph $G$ is a set $S$ of vertices such that removing $S$ and its neighborhood leaves no edge. The isolation number $\iota(G)$ of $G$ (also known as the vertex-edge domination number) is the minimum size among all…

Combinatorics · Mathematics 2025-09-01 Wayne Goddard , Michael A. Henning

For a graph $G$, a vertex subset $S$ is called a maximum generalized $k$-independent set if the induced subgraph $G[S]$ does not contain a $k$-tree as its subgraph, and the subset has maximum cardinality. The generalized $k$-independence…

Combinatorics · Mathematics 2025-09-15 Jing Huang

In this paper, we show that for any positive integer $m$ and $k\in [2]$, let $G$ be a $(2m+2k+2)$-connected graph and let $a_1,\ldots , a_m, s, t$ be any distinct vertices of $G$, there are $k$ internally disjoint $s$-$t$ paths $P_1,…

Combinatorics · Mathematics 2024-02-21 Yuzhen Qi , Jin Yan

A cycle $C$ of a graph $G$ is \emph{isolating} if every component of $G-V(C)$ is a single vertex. We show that isolating cycles in polyhedral graphs can be extended to larger ones: every isolating cycle $C$ of length $6 \leq |E(C)| < \left…

Data Structures and Algorithms · Computer Science 2020-04-21 Jan Kessler , Jens M. Schmidt

A copy of a graph $F$ is called an $F$-copy. For any graph $G$, the $F$-isolation number of $G$, denoted by $\iota(G,F)$, is the size of a smallest subset $D$ of the vertex set of $G$ such that the closed neighbourhood $N[D]$ of $D$ in $G$…

Combinatorics · Mathematics 2025-08-21 Peter Borg

A set of vertices of a graph $G$ is said to be decycling if its removal leaves an acyclic subgraph. The size of a smallest decycling set is the decycling number of $G$. Generally, at least $\lceil(n+2)/4\rceil$ vertices have to be removed…

Combinatorics · Mathematics 2023-09-22 Roman Nedela , Michaela Seifrtová , Martin Škoviera

It was shown by Beisegel, Chudnovsky, Gurvich, Milani\v{c}, and Servatius in 2022 that every induced $2$-edge path in a vertex-transitive graph closes to an induced cycle. Similar results were obtained for 3-edge paths closing to cycles in…

Combinatorics · Mathematics 2025-10-08 Martin Milanič , Đorđe Mitrović

A set $S$ of vertices in a graph $G$ is a dominating set if every vertex not in $S$ is adjacent to a vertex in $S$. If, in addition, $S$ is an independent set, then $S$ is an independent dominating set. The independent domination number…

Discrete Mathematics · Computer Science 2020-01-10 A. Akbari , S. Akbari , A. Doosthosseini , Z. Hadizadeh , Michael A. Henning , A. Naraghi
‹ Prev 1 2 3 10 Next ›