English

Additive tunnel number and primitive elements

Geometric Topology 2009-09-25 v1

Abstract

It is proven here that if the connected sum of two tunnel number one knots in the 3-sphere is a tunnel number two knot, then at least one of the summand knots has a genus two Heegaard splitting with a meridian as a primitive element. Hence this is a necessary and sufficient condition for tunnel number one knots to have additive tunnel number.

Keywords

Cite

@article{arxiv.math/9906061,
  title  = {Additive tunnel number and primitive elements},
  author = {Yoav Moriah},
  journal= {arXiv preprint arXiv:math/9906061},
  year   = {2009}
}

Comments

20 pages, 11 figures