English

Bandwidth of graphs resulting from the edge clique covering problem

Combinatorics 2019-06-21 v1

Abstract

Let n,k,bn,k,b be integers with 1k1bn1 \le k-1 \le b \le n and let Gn,k,bG_{n,k,b} be the graph whose vertices are the kk-element subsets XX of {0,,n}\{0,\dots,n\} with max(X)min(X)b\max(X)-\min(X) \le b and where two such vertices X,YX,Y are joined by an edge if max(XY)min(XY)b\max(X \cup Y) - \min(X \cup Y) \le b. These graphs are generated by applying a transformation to maximal kk-uniform hypergraphs of bandwidth bb that is used to reduce the (weak) edge clique covering problem to a vertex clique covering problem. The bandwidth of Gn,k,bG_{n,k,b} is thus the largest possible bandwidth of any transformed kk-uniform hypergraph of bandwidth bb. For bn+k12b\geq \frac{n+k-1}{2}, the exact bandwidth of these graphs is determined. For b<n+k12b<\frac{n+k-1}{2}, the bandwidth is asymptotically determined in the case of b=o(n)b=o(n) and in the case of bb growing linearly in nn with a factor β(0,0.5]\beta \in (0,0.5], where for one case only bounds could be found. It is conjectured that the upper bound of this open case is the right asymptotic value.

Keywords

Cite

@article{arxiv.1605.00450,
  title  = {Bandwidth of graphs resulting from the edge clique covering problem},
  author = {Konrad Engel and Sebastian Hanisch},
  journal= {arXiv preprint arXiv:1605.00450},
  year   = {2019}
}