Feasibility conditions on the parameters of a strongly regular graph

• Author(s): Martins, Enide Andrade ; Mano, Vasco Moço ; Vieira, Luís António de Almeida
• Date: 2011
• Persistent ID: http://hdl.handle.net/10773/6757
• Origin: RIA - Repositório Institucional da Universidade de Aveiro
• Subject(s): Strongly regular graph; Euclidean Jordan algebra; Matrix analysis
• Document Type: Article
• Language: English

Description

We consider a strongly regular graph, G, and associate a three dimensional Euclidean Jordan algebra, V, to the adjacency matrix A of G. Then, by considering convergent series of Hadamard powers of the idempotents of the unique complete system of orthogonal idempotents of V, we establish new feasibility conditions for the existence of strongly regular graphs.