Null-homologous unknottings

  • Charles Livingston

    Indiana University, Bloomington, USA
Null-homologous unknottings cover
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Every knot can be unknotted with two generalized twists; this was first proved by Ohyama. Here we prove that any knot of genus g can be unknotted with 2 null-homologous twists and that there exist genus knots that cannot be unknotted with fewer than 2 null-homologous twists.