English

Rational surgery exact triangles in Heegaard Floer homology

Geometric Topology 2026-01-13 v1

Abstract

We construct a new family of surgery exact triangles in Heegaard Floer theory over the field with two elements. This family generalizes both Ozsv\'{a}th and Szab\'{o}'s nn- and 1/n1/n-surgery exact triangles for positive integers nn and the author's recent 2-surgery exact triangle to all positive rational slopes. The construction reduces to a combinatorial problem that involves triangle and quadrilateral counting maps in a genus 1 Heegaard diagram. The main contribution of this paper is solving this combinatorial problem, which is particularly tricky for slopes rn,1/nr\neq n,1/n; one key idea is to use an involution that is closely related to the Spinc{\rm Spin}^{c} conjugation symmetry.

Keywords

Cite

@article{arxiv.2601.06654,
  title  = {Rational surgery exact triangles in Heegaard Floer homology},
  author = {Gheehyun Nahm},
  journal= {arXiv preprint arXiv:2601.06654},
  year   = {2026}
}

Comments

55 pages, 15 figures, comments welcome!