{ "id": "1703.03581", "version": "v1", "published": "2017-03-10T08:54:47.000Z", "updated": "2017-03-10T08:54:47.000Z", "title": "Some spectral properties of chain graphs", "authors": [ "Ebrahim Ghorbani" ], "categories": [ "math.CO" ], "abstract": "A graph is called a chain graph if it is bipartite and the neighborhoods of the vertices in each color class form a chain with respect to inclusion. Alazemi, Andeli\\'c and Simi\\'c conjectured that no chain graph shares a non-zero (adjacency) eigenvalue with its vertex-deleted subgraphs. We disprove this conjecture. However, we show that the assertion holds for subgraphs obtained by deleting vertices of maximum degrees in either of color classes. We also give a simple proof for the fact that chain graphs have no eigenvalue in the interval $(0,1/2)$.", "revisions": [ { "version": "v1", "updated": "2017-03-10T08:54:47.000Z" } ], "analyses": { "subjects": [ "05C50" ], "keywords": [ "spectral properties", "color class form", "chain graph shares", "simple proof", "assertion holds" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }