Let
be a simple graph with vertex set
and edges set
. A set
is a dominating
set if every vertex in
is adjacent to at least one vertex in
. An eternal 1-secure set of a graph G is defined as a dominating set
such that for any positive integer k and any sequence
of vertices, there exists a sequence of guards
with
and either
or
and
is a dominating set. If we take a guard on every vertex in an eternal 1-secure set, then for any sequence of attacks to vertices of the graph only by moving one guard during one of the edges adjacent with the vertex, the result set still remains secure. Now let for every sequence of attacks to vertices, all guards could move during one of the edges adjacent with the vertex and the result set still remains secure. This set is called eternal
- secure set. The eternal
- security number
is defined as the minimum number of an eternal
-
secure set. secure set in G. An edge
is subdivided if the edge
is deleted and a new vertex
is added, along with two new edges
and
. The eternal
- security subdivision number
of a graph
is the minimum cardinality of a set of edges that must be subdivided (where each edge in
can be subdivided at most once) in order to increase the eternal
-
security number of
to increase the eternal m- security number of G. In this paper, we show that the eternal
- security subdivision number is at most 3 for any nontrivial graph .
Type of Study:
S |
Subject:
Algebraic Graph Theory Received: 2019/11/12 | Revised: 2022/11/15 | Accepted: 2020/08/5 | Published: 2022/05/14 | ePublished: 2022/05/14