On Monitoring Edge-Geodetic Sets of Dynamic Graph

TL;DR

This paper studies how the removal of edges from a graph affects its monitoring edge-geodetic set and the number of vertices needed to monitor all edges, which is crucial for network maintenance and fault detection.

Contribution

It introduces an analysis of the impact of edge deletions on the monitoring edge-geodetic number in graphs, extending understanding of dynamic graph monitoring.

Findings

Edge deletions can increase the monitoring edge-geodetic number.

The structure of a graph influences how edge removals affect monitoring capabilities.

Strategies for updating MEG-sets after edge deletions are discussed.

Abstract

The concept of a monitoring edge-geodetic set (MEG-set) in a graph $G$, denoted $MEG(G)$, refers to a subset of vertices $MEG(G)\subseteq V(G)$ such that every edge $e$ in $G$ is monitored by some pair of vertices $ u, v \in MEG(G)$, where $e$ lies on all shortest paths between $u$ and $v$. The minimum number of vertices required to form such a set is called the monitoring edge-geodetic number, denoted $meg(G)$. The primary motivation for studying $MEG$-sets in previous works arises from scenarios in which certain edges are removed from $G$. In these cases, the vertices of the $MEG$-set are responsible for detecting these deletions. Such detection is crucial for identifying which edges have been removed from $G$ and need to be repaired. In real life, repairing these edges may be costly, or sometimes it is impossible to repair edges. In this case, the original $MEG$-set may no longer be effective in monitoring the modified graph. This highlights the importance of reassessing and adapting the $MEG$-set after edge deletions. This work investigates the monitoring edge-geodetic properties of graphs, focusing on how the removal of $k$ edges affects the structure of a graph and influences its monitoring capabilities. Specifically, we explore how the monitoring edge-geodetic number $meg(G)$ changes when $k$ edges are removed. The study aims to compare the monitoring properties of the original graph with those of the modified graph and to understand the impact of edge deletions.