Laplacian spectral characterization of roses
He,Changxiang ; van Dam,Edwin R.
He,Changxiang
van Dam,Edwin R.
Abstract
A rose graph is a graph consisting of cycles that all meet in one vertex. We show that except for two specific examples, these rose graphs are determined by the Laplacian spectrum, thus proving a conjecture posed by Liu and Huang (2013) [8]. We also show that if two rose graphs have a so-called universal Laplacian matrix with the same spectrum, then they must be isomorphic. In memory of Horst Sachs (1927–2016), we show the specific case of the latter result for the adjacency matrix by using Sachs' theorem and a new result on the number of matchings in the disjoint union of paths.
Description
Date
2018-01-01
Journal Title
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Publisher
Research Projects
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Keywords
Rose graphs, Laplacian spectrum, Closed walks, Sachs' theorem, Matchings
Citation
He, C & van Dam, E R 2018, 'Laplacian spectral characterization of roses', Linear Algebra and its Applications, vol. 536, pp. 19-30. https://doi.org/10.1016/j.laa.2017.08.012
