{ "id": "2208.12378", "version": "v1", "published": "2022-08-25T23:47:55.000Z", "updated": "2022-08-25T23:47:55.000Z", "title": "On the Burau representation of $B_3$", "authors": [ "Vasudha Bharathram", "Joan Birman" ], "comment": "15 pages, 10 figures", "categories": [ "math.GT" ], "abstract": "We study the Burau representation of the braid group $B_n$ in the case where $n=3$. We give three novel topological proofs that the Burau representation of $B_3$ is faithful, and a proof that it's faithful modulo $p$ for all integers $p>1$. We then classify conjugacy classes in the image of the Burau representation in $\\text{GL}(2, \\mathbb{Z}[t, t^{-1}])$ in a way that takes account of the fact that braids are geometrically oriented, and use that fact to give a new, linear time solution to the conjugacy problem in $B_3$. We pose several open problems about $B_n$.", "revisions": [ { "version": "v1", "updated": "2022-08-25T23:47:55.000Z" } ], "analyses": { "subjects": [ "20F36", "20F65", "20C99" ], "keywords": [ "burau representation", "linear time solution", "braid group", "conjugacy problem", "open problems" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }