English

Suspension theorems for links and link maps

Geometric Topology 2017-01-03 v3 Algebraic Topology

Abstract

We present a new short proof of the explicit formula for the group of links (and also link maps) in the 'quadruple point free' dimension. Denote by Lp,qmL^m_{p,q} (respectively, CpmpC^{m-p}_p) the group of smooth embeddings SpSqSmS^p\sqcup S^q\to S^m (respectively, SpSmS^p\to S^m) up to smooth isotopy. Denote by LMp,qmLM^m_{p,q} the group of link maps SpSqSmS^p\sqcup S^q\to S^m up to link homotopy. Theorem 1. If pqm3p\le q\le m-3 and 2p+2q3m62p+2q\le 3m-6 then \begin{equation*} L^m_{p,q}\cong \pi_p(S^{m-q-1})\oplus\pi_{p+q+2-m}(SO/SO_{m-p-1})\oplus C^{m-p}_p\oplus C^{m-q}_q. \end{equation*} Theorem 2. If p,qm3p, q\le m-3 and 2p+2q3m52p+2q\le 3m-5 then LMp,qmπp+q+1mSLM^m_{p,q}\cong \pi^S_{p+q+1-m}. Our approach is based on the use of the suspension operation for links and link maps, and suspension theorems for them.

Keywords

Cite

@article{arxiv.math/0610320,
  title  = {Suspension theorems for links and link maps},
  author = {Mikhail Skopenkov},
  journal= {arXiv preprint arXiv:math/0610320},
  year   = {2017}
}

Comments

in English and in Russian, 12 pages, 3 figures; minor correction in the definition of the vertical homomorphisms in Theorem 3.5