English

Inducibility in the hypercube

Combinatorics 2022-09-13 v1

Abstract

Let QdQ_d be the hypercube of dimension dd and let HH and KK be subsets of the vertex set V(Qd)V(Q_d), called configurations in QdQ_d. We say that KK is an \emph{exact copy} of HH if there is an automorphism of QdQ_d which sends HH onto KK. Let ndn\geq d be an integer, let HH be a configuration in QdQ_d and let SS be a configuration in QnQ_n. We let λ(H,d,n)\lambda(H,d,n) be the maximum, over all configurations SS in QnQ_n, of the fraction of sub-dd-cubes RR of QnQ_n in which SRS\cap R is an exact copy of HH, and we define the dd-cube density λ(H,d)\lambda(H,d) of HH to be the limit as nn goes to infinity of λ(H,d,n)\lambda(H,d,n). We determine λ(H,d)\lambda(H,d) for several configurations in Q3Q_3 and Q4Q_4 as well as for an infinite family of configurations. There are strong connections with the inducibility of graphs.

Keywords

Cite

@article{arxiv.2209.04740,
  title  = {Inducibility in the hypercube},
  author = {John Goldwasser and Ryan Hansen},
  journal= {arXiv preprint arXiv:2209.04740},
  year   = {2022}
}