{ "id": "1901.08048", "version": "v1", "published": "2019-01-23T18:58:20.000Z", "updated": "2019-01-23T18:58:20.000Z", "title": "A general method to obtain the spectrum and local spectra of a graph from its regular partitions", "authors": [ "C. Dalfó", "M. A. Fiol" ], "categories": [ "math.CO" ], "abstract": "It is well known that, in general, part of the spectrum of a graph can be obtained from the adjacency matrix of its quotient graph given by a regular partition. In this paper, we propose a method to obtain all the spectrum, and also the local spectra, of a graph $\\Gamma$ from the quotient matrices of some of its regular partitions. As examples, it is shown how to find the eigenvalues and (local) multiplicities of walk-regular, distance-regular, and distance-biregular graphs.", "revisions": [ { "version": "v1", "updated": "2019-01-23T18:58:20.000Z" } ], "analyses": { "subjects": [ "05E30", "05C50" ], "keywords": [ "regular partition", "local spectra", "general method", "adjacency matrix", "quotient matrices" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }