On the Energy of Certain Recursive Structures

Sudeep Stephen1, Bharati Rajan2, Mirka Miller3, Cyriac Grigorious4, Albert William5
1Department of Mathematics, Loyola College, Chennai, India
2School of Electrical Engineering and Computer Science, The University of Newcastle, Australia
3School of Mathematical and Physical Sciences, The University of Newcastle, Australia
4Department of Mathematics, University of West Bohemia, Pilsen, Czech Republic
5Department of Informatics, King’s College London, UK

Abstract

Eigenvalues of a graph are the eigenvalues of its adjacency matrix. The multiset of eigenvalues is called the \emph{spectrum}. The energy of a graph is defined as the sum of the absolute values of its eigenvalues. In this paper, we devise an algorithm that generates the adjacency matrix of \( WK \)-recursive structures \( WK(3, L) \) and \( WK(4, L) \), and use it to effectively compute the spectrum and energy of these graphs.