{ "id": "1709.09011", "version": "v1", "published": "2017-09-26T13:41:06.000Z", "updated": "2017-09-26T13:41:06.000Z", "title": "The smallest eigenvalues of Hamming graphs, Johnson graphs and other distance-regular graphs with classical parameters", "authors": [ "Andries E. Brouwer", "Sebastian M. Cioabă", "Ferdinand Ihringer", "Matt McGinnis" ], "comment": "29 pages", "categories": [ "math.CO", "cs.DM" ], "abstract": "We prove a conjecture by Van Dam and Sotirov on the smallest eigenvalue of (distance-$j$) Hamming graphs and a conjecture by Karloff on the smallest eigenvalue of (distance-$j$) Johnson graphs. More generally, we study the smallest eigenvalue and the second largest eigenvalue in absolute value of the graphs of the relations of classical $P$- and $Q$-polynomial association schemes.", "revisions": [ { "version": "v1", "updated": "2017-09-26T13:41:06.000Z" } ], "analyses": { "keywords": [ "smallest eigenvalue", "johnson graphs", "hamming graphs", "distance-regular graphs", "classical parameters" ], "note": { "typesetting": "TeX", "pages": 29, "language": "en", "license": "arXiv", "status": "editable" } } }