The graphs cospectral with the pineapple graph

Autor:	Sezer Sorgun, Hatice Topcu, Willem H. Haemers
Přispěvatelé:	Econometrics and Operations Research
Jazyk:	angličtina
Rok vydání:	2019
Předmět:	Vertex (graph theory) adjacency matrix Applied Mathematics Complete graph spectral characterization Graph Combinatorics cospectral graphs Discrete Mathematics and Combinatorics Adjacency list Adjacency matrix pineapple graph Eigenvalues and eigenvectors Mathematics
Zdroj:	Discrete Applied Mathematics, 269, 52-59. Elsevier
ISSN:	0166-218X
Popis:	The pineapple graph K p q is obtained by appending q pendant edges to a vertex of a complete graph K p ( p ≥ 3 , q ≥ 1 ). We prove that among connected graphs, the pineapple graph is determined by its adjacency spectrum. Moreover, we determine all disconnected graphs which are cospectral with a pineapple graph. Thus we find for which values of p and q the pineapple graph K p q is determined by its adjacency spectrum. The main tool is a recent classification of all graphs with all but three eigenvalues equal to 0 or − 1 by the third author.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4bee115a834b452e1e08c1286f67ed7b https://doi.org/10.1016/j.dam.2018.10.002 Zobrazit plný text záznamu Full Text from ScienceDirect