{ "id": "2207.13244", "version": "v1", "published": "2022-07-27T02:11:27.000Z", "updated": "2022-07-27T02:11:27.000Z", "title": "Kempe equivalence of almost bipartite graphs", "authors": [ "Akihiro Higashitani", "Naoki Matsumoto" ], "comment": "24 pages", "categories": [ "math.CO", "cs.DM" ], "abstract": "Two vertex colorings of a graph are Kempe equivalent if they can be transformed into each other by a sequence of switchings of two colors of vertices. It is PSPACE-complete to determine whether two given vertex $k$-colorings of a graph are Kempe equivalent for any fixed $k\\geq 3$, and it is easy to see that every two vertex colorings of any bipartite graph are Kempe equivalent. In this paper, we consider Kempe equivalence of {\\it almost} bipartite graphs which can be obtained from a bipartite graph by adding several edges to connect two vertices in the same partite set. We give a conjecture of Kempe equivalence of such graphs, and we prove several partial solutions and best possibility of the conjecture.", "revisions": [ { "version": "v1", "updated": "2022-07-27T02:11:27.000Z" } ], "analyses": { "subjects": [ "05C15", "05C35", "G.2.2" ], "keywords": [ "bipartite graph", "kempe equivalence", "kempe equivalent", "vertex colorings", "partite set" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }