Some families of integral graphs
Wang, Ligong and Broersma, Hajo and Hoede, Cornelis and Li, Xueliang and Still, Georg (2008) Some families of integral graphs. Discrete Mathematics, 308 (24). pp. 63836391. ISSN 0012365X
PDF
Restricted to UT campus only : Request a copy 644kB 
Abstract:  A graph is called integral if all its eigenvalues (of the adjacency matrix) are integers. In this paper, the graphs and the tree are defined. We determine the characteristic polynomials of these graphs and also obtain sufficient and necessary conditions for these graphs to be integral. Some sufficient conditions are found by using the number theory and computer search. All these classes are infinite. Some new results which treat interrelations between integral trees of various diameters are also found. The discovery of these integral graphs is a new contribution to the search of such graphs.

Item Type:  Article 
Copyright:  © 2008 Elsevier 
Faculty:  Electrical Engineering, Mathematics and Computer Science (EEMCS) 
Research Group:  
Link to this item:  http://purl.utwente.nl/publications/62590 
Official URL:  http://dx.doi.org/10.1016/j.disc.2007.12.010 
Export this item as:  BibTeX EndNote HTML Citation Reference Manager 
Repository Staff Only: item control page
Metis ID: 254963