{ "id": "1605.04416", "version": "v1", "published": "2016-05-14T13:23:08.000Z", "updated": "2016-05-14T13:23:08.000Z", "title": "On the similarity of AB and BA for normal and other matrices", "authors": [ "Stephan Ramon Garcia", "David Sherman", "Gary Weiss" ], "comment": "6 pages", "categories": [ "math.FA" ], "abstract": "It is well-known that AB and BA are similar when A and B are complex square Hermitian matrices. In this note we answer a question of F. Zhang by demonstrating that similarity can fail if A is Hermitian and B is normal. Perhaps surprisingly, similarity does hold when A is positive semidefinite and B is normal.", "revisions": [ { "version": "v1", "updated": "2016-05-14T13:23:08.000Z" } ], "analyses": { "subjects": [ "15A03", "15A18" ], "keywords": [ "similarity", "complex square hermitian matrices", "well-known", "positive semidefinite" ], "note": { "typesetting": "TeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable" } } }