English

CAT(0) geometry of complex curve complements and families

Geometric Topology 2024-11-28 v1 Algebraic Geometry Group Theory

Abstract

Motivated by the question of whether braid groups are CAT(0), we investigate the CAT(0) behavior of fundamental groups of plane curve complements and certain universal families. If CC is the branch locus of a generic projection of a smooth, complete intersection surface to \PP2\PP^2, we show that π1(\PP2C)\pi_1(\PP^2\setminus C) is CAT(0). In the other direction, we prove that the fundamental group of the universal family associated with the singularities of type E6E_6, E7E_7, and E8E_8 is not CAT(0).

Keywords

Cite

@article{arxiv.2411.18067,
  title  = {CAT(0) geometry of complex curve complements and families},
  author = {Corey Bregman and Anatoly Libgober and Kejia Zhu},
  journal= {arXiv preprint arXiv:2411.18067},
  year   = {2024}
}