{ "id": "1106.1134", "version": "v2", "published": "2011-06-06T18:01:33.000Z", "updated": "2011-06-13T16:18:44.000Z", "title": "Around a conjecture by R. Connelly, E. Demaine, and G. Rote", "authors": [ "Alexander Igamberdiev", "Gaiane Panina" ], "categories": [ "math.AT" ], "abstract": "Denote by $M(P)$ the configuration space of a planar polygonal linkage, that is, the space of all possible planar configurations modulo congruences, including configurations with self-intersections. A particular interest attracts its subset $M^o(P) \\subset M(P)$ of all configurations \\emph{without} self-intersections. R. Connelly, E. Demaine, and G. Rote proved that $M^o(P)$ is contractible and conjectured that so is its closure $\\bar{M^o(P)}$. We disprove this conjecture by showing that a special choice of $P$ makes the homologies $H_k(\\bar{M^o(P)})$ non-trivial.", "revisions": [ { "version": "v2", "updated": "2011-06-13T16:18:44.000Z" } ], "analyses": { "subjects": [ "55M99" ], "keywords": [ "conjecture", "planar configurations modulo congruences", "planar polygonal linkage", "special choice", "interest attracts" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1106.1134I" } } }