English

Non-realizability of the pure braid group as area-preserving homeomorphisms

Geometric Topology 2020-02-26 v1 Dynamical Systems

Abstract

Let Homeo+(Dn2)\text{Homeo}_+(D^2_n) be the group of orientation-preserving homeomorphisms of D2D^2 fixing the boundary pointwise and nn marked points as a set. Nielsen realization problem for the braid group asks whether the natural projection pn:Homeo+(Dn2)Bn:=π0(Homeo+(Dn2))p_n:\text{Homeo}_+(D^2_n)\to B_n:=\pi_0(\text{Homeo}_+(D^2_n)) has a section over subgroups of BnB_n. All of the previous methods either use torsions or Thurston stability, which do not apply to the pure braid group PBnPB_n, the subgroup of BnB_n that fixes nn marked points pointwise. In this paper, we show that the pure braid group has no realization inside the area-preserving homeomorphisms using rotation numbers.

Keywords

Cite

@article{arxiv.2002.10918,
  title  = {Non-realizability of the pure braid group as area-preserving homeomorphisms},
  author = {Lei Chen},
  journal= {arXiv preprint arXiv:2002.10918},
  year   = {2020}
}

Comments

12 pages. arXiv admin note: text overlap with arXiv:1904.09490