DETERMINING THE LAPLACIAN SPECTRUM IN PARTICULAR CLASSES OF GRAPHS
MIHAI TALMACIU Department of Mathematics and Informatics, Faculty of Sciences, "Vasile Alecsandri" University of Bacău, 157 Calea Mărășești, 600115 Bacău, ROMANIA,
e-mail: mtalmaciu@ub.ro
During the last three decades, different types of decompositions have been processed in the field of graph theory. Among these we mention: decompositions based on the addi-tivity of some characteristics of the graph, decompositions where the adjacency law be-tween the subsets of the partition is known, decompositions where the subgraph induced by every subset of the partition must have predeterminate properties, as well as combina-tions of such decompositions. In this paper we characterize threshold graphs using the weakly decomposition, determine the Laplacian spectrum in threshold graphs.
