{ "id": "1807.07976", "version": "v1", "published": "2018-07-20T18:00:20.000Z", "updated": "2018-07-20T18:00:20.000Z", "title": "On the discontinuity of the $π_1$-action", "authors": [ "Jeremy Brazas" ], "comment": "13 pages", "categories": [ "math.AT", "math.GN" ], "abstract": "We show the classical $\\pi_1$-action on the $n$-th homotopy group can fail to be continuous for any $n$ when the homotopy groups are equipped with the natural quotient topology. In particular, we prove the action $\\pi_1(X)\\times\\pi_n(X)\\to\\pi_n(X)$ fails to be continuous for a one-point union $X=A\\vee \\mathbb{H}_n$ where $A$ is an aspherical space such that $\\pi_1(A)$ is a topological group and $\\mathbb{H}_n$ is the $(n-1)$-connected, n-dimensional Hawaiian earring space $\\mathbb{H}_n$ for which $\\pi_n(\\mathbb{H}_n)$ is a topological abelian group.", "revisions": [ { "version": "v1", "updated": "2018-07-20T18:00:20.000Z" } ], "analyses": { "subjects": [ "55Q52", "14F35" ], "keywords": [ "discontinuity", "th homotopy group", "natural quotient topology", "n-dimensional hawaiian earring space", "topological abelian group" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }