English

A note on surfaces in $\mathbb{CP}^2$ and $\mathbb{CP}^2\# \mathbb{CP}^2$

Geometric Topology 2025-04-08 v2

Abstract

In this brief note, we investigate the CP2\mathbb{CP}^2-genus of knots, i.e. the least genus of a smooth, compact, orientable surface in CP2B4˚\mathbb{CP}^2\setminus \mathring{B^4} bounded by a knot in S3S^3. We show that this quantity is unbounded, unlike its topological counterpart. We also investigate the CP2\mathbb{CP}^2-genus of torus knots. We apply these results to improve the minimal genus bound for some homology classes in CP2#CP2\mathbb{CP}^2\# \mathbb{CP}^2.

Keywords

Cite

@article{arxiv.2210.12486,
  title  = {A note on surfaces in $\mathbb{CP}^2$ and $\mathbb{CP}^2\# \mathbb{CP}^2$},
  author = {Marco Marengon and Allison N. Miller and Arunima Ray and András I. Stipsicz},
  journal= {arXiv preprint arXiv:2210.12486},
  year   = {2025}
}

Comments

7 pages, 3 figures; v2: minor modifications following a referee report, this is the version accepted to appear in Proc. AMS

R2 v1 2026-06-28T04:15:29.574Z