Irreversible $k$-Threshold Conversion Number of Corona Product and Double Corona Product Graphs

Abstract: This paper studies the irreversible $k$-threshold process on graphs, where a vertex becomes colored if at least $k$ neighbors are colored and remains colored indefinitely. We investigate vertex sets that, when initially colored, lead to a completely colored graph. The graphs under initial consideration are constructed using the corona product of cyclic graphs and complete graphs. We then introduce and explore double corona product graphs (of cyclic graphs and complete graphs) to study more complex topologies and their impact on the coloring propagation. We further extend the theory by introducing a probabilistic approach to the coloring dynamics. Our findings provide insights into the interplay between graph structure and saturation dynamics by extending the theory to new families of graphs and introducing a probabilistic approach with potential applications in epidemiology and social influence modeling.