{ "id": "1208.1994", "version": "v2", "published": "2012-08-09T18:37:10.000Z", "updated": "2012-09-10T00:55:55.000Z", "title": "A non-abelian analogue of Whitney's 2-isomorphism theorem", "authors": [ "Eric Katz" ], "comment": "7 pages", "categories": [ "math.CO" ], "abstract": "We give a non-abelian analogue of Whitney's 2-isomorphism theorem for graphs. Whitney's theorem states that the cycle space determines a graph up to 2-isomorphism. Instead of considering the cycle space of a graph which is an abelian object, we consider a mildly non-abelian object, the 2-truncation of the group algebra of the fundamental group of the graph considered as a subalgebra of the 2-truncation of the group algebra of the free group on the edges. The analogue of Whitney's theorem is that this is a complete invariant of 2-edge connected graphs: let G,G' be 2-edge connected finite graphs; if there is a bijective correspondence between the edges of G and G' that induces equality on the 2-truncations of the group algebras of the fundamental groups, then G and G' are isomorphic.", "revisions": [ { "version": "v2", "updated": "2012-09-10T00:55:55.000Z" } ], "analyses": { "keywords": [ "non-abelian analogue", "group algebra", "fundamental group", "whitneys theorem states", "cycle space determines" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1208.1994K" } } }