2020/02/23 by Lei Chen, Chen, Lei
Mathematics · #Algebraic Geometry and Number Theory #Dynamical Systems (math.DS) #FOS: Mathematics #Geometric Topology (math.GT) #Geometric and Algebraic Topology #Homotopy and Cohomology in Algebraic Topology
paper · pdf · doi:10.48550/arxiv.2002.10918
openalex publication_date 2020/02/23 · openalex created_date 2022/10/30 · openalex updated_date 2026/07/28
Let Homeo+(D2n) be the group of orientation-preserving homeomorphisms of D2 fixing the boundary pointwise and n marked points as a set. Nielsen realization problem for the braid group asks whether the natural projection pn:Homeo+(D2n)→ Bn:=π0(Homeo+(D2n)) has a section over subgroups of Bn. All of the previous methods either use torsions or Thurston stability, which do not apply to the pure braid group PBn, the subgroup of Bn that fixes n marked points pointwise. In this paper, we show that the pure braid group has no realization inside the area-preserving homeomorphisms using rotation numbers.