Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-27T02:39:53.824Z Has data issue: false hasContentIssue false

Examples of tunnel number one knots which have the property ‘1 + 1 = 3’

Published online by Cambridge University Press:  24 October 2008

Kanji Morimoto
Affiliation:
Department of Mathematics, Takushoku University, Tatemachi, Hachioji, Tokyo 193, Japan
Makoto Sakuma
Affiliation:
Department of Mathematics, Faculty of Science. Osaka University, Machikaneyama-cho 1-16, Toyonaka, Osaka 560, Japan
Yoshiyuki Yokota
Affiliation:
Graduate School of Mathematics, Kyushu University, Fukuoka 812, Japan

Extract

Let K be a knot in the 3-sphere S3, N(K) the regular neighbourhood of K and E(K) = cl(S3N(K)) the exterior of K. The tunnel number t(K) is the minimum number of mutually disjoint arcs properly embedded in E(K) such that the complementary space of a regular neighbourhood of the arcs is a handlebody. We call the family of arcs satisfying this condition an unknotting tunnel system for K. In particular, we call it an unknotting tunnel if the system consists of a single arc.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Boileau, M.. Lustig, M. and Moriah, Y.. Links with super-additive tunnel number (preprint).Google Scholar
[2]Boileau, M.. Rost, M. and Zieschang, H.. On Heegaard decompositions of torus knot exteriors and related Seifert fibre spaces. Math. Ann. 279 (1988), 553581.CrossRefGoogle Scholar
[3]Doll, H.. A generalized bridge number for links in 3-manifolds. Math. Ann. 294 (1992), 701717.CrossRefGoogle Scholar
[4]Haken, V.. Some reaultn on surface in 3-manifolds, Studies in Modern Topology, Math. Assoc. Amer. (Prentice-Hall. 1968).Google Scholar
[5]Jones, A. C.. Composite two-generator links have a Hopf link summand (preprint).Google Scholar
[6]Jokes, V. F. R.. Hecke algebra representations of braid groups and link polynomials. Ann. Math. 126 (1987), 335388.Google Scholar
[7]Kauffman, L. H.. State models and the Jones polynomials. Topology 26 (1987), 395407.CrossRefGoogle Scholar
[8]Kobayashi, T.. Arbitrarily highly degenerations of tunnel numbers of knots, to appear in Knot Ramifications.Google Scholar
[9]Kohno, T.. Tunnel number of knots and Jones-Whitten invariants (preprint).Google Scholar
[10]Montesinos, J. M.. Surgery on links and double branched covers of S3. Ann. Math. Studies 84 (1975), 227259.Google Scholar
[11]Moriah, Y. and Rubinstein, H.. Heegaard structures of negatively curved 3-manifoIds (preprint).Google Scholar
[12]Morimoto, K.. On the additivity of tunnel number of knots. Topology Appl. 53 (1993), 3766.CrossRefGoogle Scholar
[13]Morimoto, K.. There are knots whose tunnel numbers go down under connected sum, to appear in Proc. A M.S.Google Scholar
[14]Morimoto, K. and Sakuma, M.. On unknotting tunnels for knots. Math. Ann. 289 (1991), 143167.CrossRefGoogle Scholar
[15]Norwood, F. H.. Every two generator knot is prime. Proc. A.M.S. 86 (1982), 143147.CrossRefGoogle Scholar
[16]Scharlemann, M.. Tunnel number one knots satisfy the Poenaru conjecture. Topology Appl. 18 (1984), 235258.CrossRefGoogle Scholar
[17]Yokota, Y.. Twisting formulae of the Jones polynomial. Math. Proc. Camb. Phil. Soc. 110 (1991), 473482.CrossRefGoogle Scholar
[18]Yokota, Y.. On quantum SU(2) invariants and generalized bridge numbers of knots. Math. Proc. Camb. Phil. Soc. 117 (1995), 545557.CrossRefGoogle Scholar