{ "id": "math/0606542", "version": "v3", "published": "2006-06-21T19:32:15.000Z", "updated": "2009-04-27T14:09:21.000Z", "title": "The Karoubi envelope and Lee's degeneration of Khovanov homology", "authors": [ "Dror Bar-Natan", "Scott Morrison" ], "comment": "This is the version published by Algebraic & Geometric Topology on 4 October 2006", "journal": "Algebr. Geom. Topol. 6 (2006) 1459-1469", "doi": "10.2140/agt.2006.6.1459", "categories": [ "math.GT" ], "abstract": "We give a simple proof of Lee's result from [Adv. Math. 179 (2005) 554-586; arXiv:math.GT/0210213], that the dimension of the Lee variant of the Khovanov homology of a c-component link is 2^c, regardless of the number of crossings. Our method of proof is entirely local and hence we can state a Lee-type theorem for tangles as well as for knots and links. Our main tool is the \"Karoubi envelope of the cobordism category\", a certain enlargement of the cobordism category which is mild enough so that no information is lost yet strong enough to allow for some simplifications that are otherwise unavailable.", "revisions": [ { "version": "v3", "updated": "2009-04-27T14:09:21.000Z" } ], "analyses": { "subjects": [ "57M25", "18E05", "57M27" ], "keywords": [ "khovanov homology", "karoubi envelope", "lees degeneration", "cobordism category", "simple proof" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......6542B" } } }