Laplacian Eigenvalues of Threshold Graphs and Majorization
Hawa Ahmed Alrawayati
Department of Mathematics, Faculty of Science, Misurata University, Libya.
Ümit Tokeşer *
Department of Mathematics, Faculty of Science, Kastamonu University, 37100, Kastamonu, Turkey.
*Author to whom correspondence should be addressed.
Abstract
This paper investigates the relationship between Laplacian eigenvalues of threshold graphs and the concept of majorization. Threshold graphs, characterized by their simplicity and combinatorial properties, serve as a rich framework for exploring spectral graph theory. We analyze the Laplacian matrix of these graphs and derive conditions under which the eigenvalues exhibit majorization properties. By employing techniques from linear algebra and combinatorial optimization, we establish a set of inequalities that describe the distribution of the Laplacian eigenvalues in terms of the graph's structural parameters. Furthermore, we demonstrate how these relationships can be utilized to infer properties of the graph, such as connectedness and robustness. Our findings contribute to the broader understanding of spectral properties in graph theory and open avenues for further research into the implications of majorization in combinatorial structures. The results have potential applications in network analysis, particularly in assessing the resilience of networks modeled by threshold graphs.
Keywords: Graph, threshold graph, laplacian matrix, majorization