Genus two Heegaard splittings of orientable three-manifolds
Genus two Heegaard splittings of orientable three-manifolds
It was shown by Bonahon–Otal and Hodgson–Rubinstein that any two genus–one Heegaard splittings of the same 3–manifold (typically a lens space) are isotopic. On the other hand, it was shown by Boileau, Collins and Zieschang that certain Seifert manifolds have distinct genus– two Heegaard splittings. In an earlier paper, we …