English

The bunkbed conjecture on the complete graph

Combinatorics 2021-03-30 v4

Abstract

The bunkbed conjecture was first posed by Kasteleyn. If G=(V,E)G=(V,E) is a finite graph and HH some subset of VV, then the bunkbed of the pair (G,H)(G,H) is the graph G×{1,2}G\times\{1,2\} plus H|H| extra edges to connect for every vHv\in H the vertices (v,1)(v,1) and (v,2)(v,2). The conjecture asserts that (v,1)(v,1) is more likely to connect with (w,1)(w,1) than with (w,2)(w,2) in the independent bond percolation model for any v,wVv,w\in V. This is intuitive because (v,1)(v,1) is in some sense closer to (w,1)(w,1) than it is to (w,2)(w,2). The conjecture has however resisted several attempts of proof. This paper settles the conjecture in the case of a constant percolation parameter and GG the complete graph.

Keywords

Cite

@article{arxiv.1803.07647,
  title  = {The bunkbed conjecture on the complete graph},
  author = {Peter van Hintum and Piet Lammers},
  journal= {arXiv preprint arXiv:1803.07647},
  year   = {2021}
}

Comments

3 pages; replaced with final version

R2 v1 2026-06-23T00:59:31.050Z