On knot Floer width and Turaev genus

Abstract

To each knot K S3 one can associate with its knot Floer homology HFK^(K), a finitely generated bigraded abelian group. In general, the nonzero ranks of these homology groups lie on a finite number of slope one lines with respect to the bigrading. The width of the homology is, in essence, the largest horizontal distance between two such lines. Also, for each diagram D of K there is an associated Turaev surface, and the Turaev genus is the minimum genus of all Turaev surfaces for K. We show that the width of knot Floer homology is bounded by Turaev genus plus one. Skein relations for genus of the Turaev surface and width of a complex that generates knot Floer homology are given. © 2008 Algebraic & Geometric Topology.