English

Completely independent spanning trees in the hypercube

Combinatorics 2024-12-17 v1 Discrete Mathematics

Abstract

We say two spanning trees of a graph are completely independent if their edge sets are disjoint, and for each pair of vertices, the paths between them in each spanning tree do not have any other vertex in common. Pai and Chang constructed two such spanning trees in the hypercube QnQ_n for sufficiently large nn, while Kandekar and Mane recently showed there are 33 pairwise completely independent spanning trees in hypercubes QnQ_n for sufficiently large nn. We prove that for each kk, there exist kk completely independent spanning trees in QnQ_n for sufficiently large nn. In fact, we show that there are (112+o(1))n(\frac{1}{12}+o(1))n spanning trees in QnQ_n, each with diameter (2+o(1))n(2+o(1))n. As the minimal diameter of any spanning tree of QnQ_n is 2n12n-1, this diameter is asymptotically optimal. We prove a similar result for the powers HnH^n of any fixed graph HH.

Keywords

Cite

@article{arxiv.2412.11780,
  title  = {Completely independent spanning trees in the hypercube},
  author = {Benedict Randall Shaw},
  journal= {arXiv preprint arXiv:2412.11780},
  year   = {2024}
}

Comments

16 pages, 1 figure

R2 v1 2026-06-28T20:37:01.334Z