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