Heegaard Floer homology and maximal twisting numbers
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 , 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 . 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 -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}
}