The energy of a graph/matrix is the sum of the absolute values of its eigenvalues. We investigate the result of duplicating/removing an edge to the energy of a graph. We also deal with the problem that which graphs G have the property that if the edges of G are covered by some subgraphs, then the en
On the sum of k largest singular values of graphs and matrices
โ Scribed by Vladimir Nikiforov
- Publisher
- Elsevier Science
- Year
- 2011
- Tongue
- English
- Weight
- 164 KB
- Volume
- 435
- Category
- Article
- ISSN
- 0024-3795
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โฆ Synopsis
In the recent years, the trace norm of graphs has been extensively studied under the name of graph energy. The trace norm is just one of the Ky Fan k-norms, given by the sum of the k largest singular values, which are studied more generally in the present paper. Several relations to chromatic number, spectral radius, spread, and to other fundamental parameters are outlined. Some results are extended to more general matrices.
๐ SIMILAR VOLUMES
With the help of the undirected graph of a matrix we establish new theorems for estimating the singular values. The location of singular values of a matrix A is described in terms of its deleted absolute row sums and column sums. The formulation has an appearance analogous to Brauer's and Brualdi's