ABSTRACT
The concept of L-energy is a concept that stems from energy of graphs. The energy of a graph is defined with the help of adjacency matrix. The Laplacian matrix of the graph includes a diagonal matrix with a specific entry as the degree of a vertex. The L-spectra of the graph includes the collection of eigen values of the Laplacian matrix together with their multiplicities. This chapter investigates the L-spectra for the graphs obtained by means of duplication of graph elements. It considers simple, finite and undirected graphs. The chapter discusses the L-spectra of the graph that is obtained by duplicating each vertex by an edge and by duplicating each edge by the vertex. It also investigates L-spectra for the larger graphs by duplication of graph elements for any k-regular graph.
