English

Homotopy types of Vietoris-Rips complexes of Hypercube Graphs

Combinatorics 2023-05-15 v1

Abstract

We describe the homotopy types of Vietoris-Rips complexes of hypercube graphs at scale 33. We represent the vertices in the hypercube graph QmQ_m as the collection of all subsets of [m]={1,2,,m}[m]=\{1, 2, \ldots, m\} and equip QmQ_m with the metric using symmetric difference distance. It is proved in \cite{AA22} that the Vietoris-Rips complexes of hypercube graphs QmQ_m at scale 22, VR(Qm;2)\mathcal{VR}(Q_m; 2), is homotopy equivalent to cmc_m-many spheres with dimension 33 where cm=0j<i<m(j+1)(2m22i1)c_m=\sum_{0\leq j< i<m} (j+1)(2^{m-2}-2^{i-1}). Questions are raised in \cite{AA22} for determining the homotopy types of VR(Qm,r)\mathcal{VR}(Q_m, r) with large scales r=3,4,,m2r=3, 4, \ldots, m-2. We prove that for m5m\geq 5, VR(Qm;3)(2m4(m4)S7)(i=4m12i4(i4)S4).\mathcal{VR}(Q_m; 3)\simeq (\bigvee_{2^{m-4}\cdot{m\choose 4}} S^7) \vee (\bigvee_{\sum_{i=4}^{m-1}2^{i-4}\cdot{i\choose 4}} S^4).

Keywords

Cite

@article{arxiv.2305.07084,
  title  = {Homotopy types of Vietoris-Rips complexes of Hypercube Graphs},
  author = {Ziqin Feng},
  journal= {arXiv preprint arXiv:2305.07084},
  year   = {2023}
}