Albertson energy and Albertson Estrada index of graphs

Abstract

‎Let $G$ be a graph of order $n$ with vertices labeled as $v_1‎, ‎v_2,dots‎ , ‎v_n$‎. ‎Let $d_i$ be the degree of the vertex $v_i$ for $i = 1‎, ‎2‎, ‎cdots‎ , ‎n$‎. ‎The Albertson matrix of $G$ is the square matrix of order $n$ whose $(i‎, ‎j)$-entry is equal to $|d_i‎ - ‎d_j|$ if $v_i $ is adjacent to $v_j$ and zero‎, ‎otherwise‎. ‎The main purposes of this paper is to introduce the Albertson energy and Albertson-Estrada index of a graph‎, ‎both base on the eigenvalues of the Albertson matrix‎. ‎Moreover‎, ‎we establish upper and lower bounds for these new graph invariants and relations between them‎‎.