{ "id": "1310.5054", "version": "v2", "published": "2013-10-18T15:18:01.000Z", "updated": "2013-10-22T17:34:39.000Z", "title": "On the degeneration of tunnel numbers under connected sum", "authors": [ "Tao Li", "Ruifeng Qiu" ], "comment": "17 pages, 3 figures", "categories": [ "math.GT" ], "abstract": "We show that, for any integer $n\\ge 3$, there is a prime knot $k$ such that (1) $k$ is not meridionally primitive, and (2) for every $m$-bridge knot $k'$ with $m\\leq n$, the tunnel numbers satisfy $t(k\\# k')\\le t(k)$. This gives counterexamples to a conjecture of Morimoto and Moriah on tunnel number under connected sum and meridionally primitive knots.", "revisions": [ { "version": "v2", "updated": "2013-10-22T17:34:39.000Z" } ], "analyses": { "subjects": [ "57N10", "57M25" ], "keywords": [ "connected sum", "degeneration", "tunnel numbers satisfy", "prime knot", "bridge knot" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1310.5054L" } } }