Title
The characteristic polynomial of a generalized join graph.
Abstract
For a graph G with adjacency matrix A(G) and degree-diagonal matrix D(G), Cvetković et al introduced a bivariate polynomial ϕG(x,t)=det(xI−(A(G)−tD(G))), where I is the identity matrix. The polynomial ϕG(x, t) not only generalizes the characteristic polynomials of some well-known matrices related to G, such as the adjacency, the Laplacian matrices, but also has an elegant combinatorial interpretation as being equivalent to the Bartholdi zeta function. Let G=H[G1,G2,…,Gk] be the generalized join graph of G1,G2,…,Gk determined by graph H. In this paper, we first give a decomposition formula for ϕG(x, t). The decomposition formula provides us a new method to construct infinitely many pairs of non-regular ϕ-cospectral graphs. Then, as applications, explicit expressions for ϕG(x, t) of some special kinds of graphs are given.
Year
DOI
Venue
2019
10.1016/j.amc.2018.12.013
Applied Mathematics and Computation
Keywords
Field
DocType
The (generalized) characteristic polynomial,The generalized join graph,Cospectral
Adjacency list,Adjacency matrix,Characteristic polynomial,Combinatorics,Riemann zeta function,Polynomial,Mathematical analysis,Matrix (mathematics),Identity matrix,Mathematics,Laplace operator
Journal
Volume
ISSN
Citations 
348
0096-3003
0
PageRank 
References 
Authors
0.34
2
2
Name
Order
Citations
PageRank
Yu Chen131.40
HaiYan Chen2415.31