RT Journal Article T1 Spectral properties of geometric-arithmetic index A1 Rodríguez García, José Manuel A1 Sigarreta Almira, José María AB The concept of geometric-arithmetic index was introduced in the chemical graph theory recently, but it has shown to be useful. One of the main aims of algebraic graph theory is to determine how, or whether, properties of graphs are reflected in the algebraic properties of some matrices. The aim of this paper is to study the geometric-arithmetic index GA(1) from an algebraic viewpoint. Since this index is related to the degree of the vertices of the graph, our main tool will be an appropriate matrix that is a modification of the classical adjacency matrix involving the degrees of the vertices. Moreover, using this matrix, we define a GA Laplacian matrix which determines the geometric-arithmetic index of a graph and satisfies properties similar to the ones of the classical Laplacian matrix. (C) 2015 Elsevier Inc. All rights reserved. PB Elsevier SN 0096-3003 YR 2016 FD 2016-03-20 LK https://hdl.handle.net/10016/32620 UL https://hdl.handle.net/10016/32620 LA eng NO This research was supported in part by a Grant from Ministerio de Economía y Competitividad (MTM 2013-46374-P), Spain, and a Grant from CONACYT (FOMIX-CONACyT-UAGro 249818), México. DS e-Archivo RD 27 jul. 2024