For each g ≥ 2 there is a 3–manifold with two genus–g Heegaard splittings that
require g stabilizations to become equivalent. Previously known examples
required at most one stabilization before becoming equivalent. Control of
families of Heegaard surfaces is obtained through a deformation to harmonic
maps.
Received: 22 April 2008
Revised: 9 February 2009
Accepted: 17 January 2009
Published: 26 April 2009
Proposed: Joan Birman
Seconded: Jean-Pierre Otal, Ron Stern