{ "id": "1309.5178", "version": "v2", "published": "2013-09-20T05:46:44.000Z", "updated": "2014-08-14T02:05:19.000Z", "title": "Edge-signed graphs with smallest eigenvalue greater than -2", "authors": [ "Gary Greaves", "Jack Koolen", "Akihiro Munemasa", "Yoshio Sano", "Tetsuji Taniguchi" ], "comment": "25 pages", "doi": "10.1016/j.jctb.2014.07.006", "categories": [ "math.CO" ], "abstract": "We give a structural classification of edge-signed graphs with smallest eigenvalue greater than -2. We prove a conjecture of Hoffman about the smallest eigenvalue of the line graph of a tree that was stated in the 1970s. Furthermore, we prove a more general result extending Hoffman's original statement to all edge-signed graphs with smallest eigenvalue greater than -2. Our results give a classification of the special graphs of fat Hoffman graphs with smallest eigenvalue greater than -3.", "revisions": [ { "version": "v2", "updated": "2014-08-14T02:05:19.000Z" } ], "analyses": { "keywords": [ "smallest eigenvalue greater", "edge-signed graphs", "result extending hoffmans original statement", "general result extending hoffmans original", "fat hoffman graphs" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1309.5178G" } } }