English

Partitioning the vertices of a torus into isomorphic subgraphs

Combinatorics 2020-06-16 v3

Abstract

Let HH be an induced subgraph of the torus CkmC_k^m. We show that when k3k \ge 3 is even and V(H)|V(H)| divides some power of kk, then for sufficiently large nn the torus CknC_k^n has a perfect vertex-packing with induced copies of HH. On the other hand, disproving a conjecture of Gruslys, we show that when kk is odd and not a prime power, then there exists HH such that V(H)|V(H)| divides some power of kk, but there is no nn such that CknC_k^n has a perfect vertex-packing with copies of HH. We also disprove a conjecture of Gruslys, Leader and Tan by exhibiting a subgraph HH of the kk-dimensional hypercube QkQ_k, such that there is no nn for which QnQ_n has a perfect edge-packing with copies of HH.

Keywords

Cite

@article{arxiv.1710.07255,
  title  = {Partitioning the vertices of a torus into isomorphic subgraphs},
  author = {Marthe Bonamy and Natasha Morrison and Alex Scott},
  journal= {arXiv preprint arXiv:1710.07255},
  year   = {2020}
}

Comments

17 pages, 3 figures