The largest eigenvalues a b s t r a c t We consider the class of graphs whose each component is either a proper subgraph of some Smith graphs, or belongs to a precized subset of Smith graphs. We classify the graphs from the considered class into those which are determined, or not determined, by Lap
Some results on the Laplacian spectrum
β Scribed by Muhuo Liu; Bolian Liu
- Book ID
- 104008861
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 290 KB
- Volume
- 59
- Category
- Article
- ISSN
- 0898-1221
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β¦ Synopsis
A graph is called a Laplacian integral graph if the spectrum of its Laplacian matrix consists of integers, and a graph G is said to be determined by its Laplacian spectrum if there does not exist other non-isomorphic graph H such that H and G share the same Laplacian spectrum. In this paper, we obtain a sharp upper bound for the algebraic connectivity of a graph, and identify all the Laplacian integral unicyclic, bicyclic graphs. Moreover, we show that all the Laplacian integral unicyclic, bicyclic graphs are determined by their Laplacian spectra.
π SIMILAR VOLUMES
In this paper we give two results concerning the signless Laplacian spectra of simple graphs. Firstly, we give a combinatorial expression for the fourth coefficient of the (signless Laplacian) characteristic polynomial of a graph. Secondly, we consider limit points for the (signless Laplacian) eigen