The $CFK^\infty$ Type of Almost L-space Knots

Abstract

Heegaard Floer homology and knot Floer homology are powerful invariants of 3-manifolds and links respectively. L-space knots are knots which admit Dehn surgeries to 3-manifolds with Heegaard Floer homology of minimal rank. In this paper we study almost L-space knots, which are knots admitting large Dehn surgeries to 3-manifolds with Heegaard Floer homology of next-to-minimal rank. Our main result is a classification of the $CFK^\infty$ type of almost L-space knots. As corollaries we show that almost L-space knots satisfy various topological properties, including some given by Baldwin-Sivek. We also give some new cable link detection results.