English

Heegaard Floer homology and maximal twisting numbers

Geometric Topology 2026-05-04 v1 Symplectic Geometry

Abstract

We adapt the Ozsv\'ath-Szab\'o full path algorithm to every star-shaped graph and establish a correspondence between negative-twisting tight contact structures on any Seifert fibred space over S2S^2, and its Heegaard Floer homology groups equipped with the Alexander filtration induced by the regular fibre. This provides the complete classification of negative-twisting structures on these manifolds; in particular, we distinguish them by their contact invariant c+c^+. We prove that every such structure is symplectically fillable and extend a known obstruction to Stein fillability. In addition, we show that the number of negative-twisting structures can be expressed combinatorially in terms of the Seifert coefficients of the star-shaped graph, while their d3d_3-invariant and homotopy type are determined explicitly through our correspondence. Our results also complete the classification of fillable structures on any small Seifert fibred space.

Keywords

Cite

@article{arxiv.2604.28162,
  title  = {Heegaard Floer homology and maximal twisting numbers},
  author = {Alberto Cavallo and Irena Matkovič},
  journal= {arXiv preprint arXiv:2604.28162},
  year   = {2026}
}