English

Short proof that Kneser graphs are Hamiltonian for $n\geq 4k$

Combinatorics 2019-12-18 v1

Abstract

For integers nk1n\geq k\geq 1, the Kneser graph K(n,k)K(n,k) is the graph with vertex set V=[n](k)V=[n]^{(k)} and edge set E={{x,y}V(2):xy=}E=\{\{x,y\} \in V^{(2)}: x\cap y=\emptyset\}. Chen proved that for n3kn\geq 3k, Kneser graphs are Hamiltonian and later improved this to n2.62k+1n\geq 2.62k+1. Furthermore, Chen and F\"uredi gave a short proof that if knk | n, Kneser graphs are Hamiltonian for n3kn\geq 3k. In this note, we present a short proof that does not need the divisibility condition, i.e., we give a short proof that K(n,k)K(n,k) is Hamiltonian for n4kn\geq 4k.

Keywords

Cite

@article{arxiv.1912.08186,
  title  = {Short proof that Kneser graphs are Hamiltonian for $n\geq 4k$},
  author = {Johann Bellmann and Bjarne Schülke},
  journal= {arXiv preprint arXiv:1912.08186},
  year   = {2019}
}

Comments

3 pages