English

Monopoles and transverse knots

Geometric Topology 2024-04-15 v2 Symplectic Geometry

Abstract

We present a framework for studying transverse knots and symplectic surfaces utilizing the Seiberg-Witten monopole equation. Our primary approach involves investigating an equivariant Seiberg-Witten theory introduced by Baraglia-Hekmati on branched covers, incorporating invariant contact/symplectic structures. Within this framework, we introduce a novel slice-torus invariant denoted as qM(K)q_M(K). This invariant can be viewed as the Seiberg-Witten analog of Hendricks-Lipshitz-Sarker's qτq_\tau invariant, with a signature correction term. One property of the invariant qM(K)q_M(K) is an adjunction equality for properly embedded connected symplectic surfaces in the symplectic filling D4#mCP2D^4\# m \overline{\mathbb{C}P}^2. The proof of this equality utilizes the equivariant version of the homotopical contact invariant introduced by the authors, leading to a transverse knot invariant. Another ingredient of the proof involves constructing invariant symplectic structures on branched covering spaces branched along properly embedded symplectic surfaces in symplectic fillings. As an application of the invariant qM(K)q_M(K), we determine the value of any slice-torus invariant within a permissible deviation of 22 for squeezed knots concordant to certain Montesinos knots. Additionally, we provide an obstruction to realizing second homology classes of D4#mCP2D^4 \#m \overline{\mathbb{C}P}^2 as connected embedded symplectic surfaces with transverse knot boundary or connected embedded Lagrangian surfaces with collarable Legendrian knot boundary. Moreover, we introduce a new obstruction to certain Montesinos knots being quasipositive, which is described only in terms of slice genera and their signatures.

Keywords

Cite

@article{arxiv.2403.15763,
  title  = {Monopoles and transverse knots},
  author = {Nobuo Iida and Masaki Taniguchi},
  journal= {arXiv preprint arXiv:2403.15763},
  year   = {2024}
}

Comments

58 pages, typo corrected

R2 v1 2026-06-28T15:30:55.525Z