{ "id": "0912.5348", "version": "v1", "published": "2009-12-29T17:58:55.000Z", "updated": "2009-12-29T17:58:55.000Z", "title": "Free Knots and Parity", "authors": [ "Vassily Olegovich Manturov" ], "comment": "18 pages;12 Figures", "categories": [ "math.GT", "math.CO" ], "abstract": "We consider knot theories possessing a {\\em parity}: each crossing is decreed {\\em odd} or {\\em even} according to some universal rule. If this rule satisfies some simple axioms concerning the behaviour under Reidemeister moves, this leads to a possibility of constructing new invariants and proving minimality and non-triviality theorems for knots from these classes, and constructing maps from knots to knots. Our main example is virtual knot theory and its simplifaction, {\\em free knot theory}. By using Gauss diagrams, we show the existence of non-trivial free knots (counterexample to Turaev's conjecture), and construct simple and deep invariants made out of parity. Some invariants are valued in graph-like objects and some other are valued in groups. We discuss applications of parity to virtual knots and ways of extending well-known invariants. The existence of a non-trivial parity for classical knots remains an open problem.", "revisions": [ { "version": "v1", "updated": "2009-12-29T17:58:55.000Z" } ], "analyses": { "subjects": [ "57M25", "57M27" ], "keywords": [ "invariants", "non-trivial free knots", "virtual knot theory", "free knot theory", "open problem" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0912.5348O" } } }