English

Factoring complete graphs and hypergraphs into factors with few maximal cliques

Combinatorics 2023-09-07 v1

Abstract

For integers r,t2r,t\geq2 and n1n\geq1 let fr(t,n)f_r(t,n) be the minimum, over all factorizations of the complete rr-uniform hypergraph of order nn into tt factors H1,,HtH_1,\dots,H_t, of i=1tc(Hi)\sum_{i=1}^tc(H_i) where c(Hi)c(H_i) is the number of maximal cliques in HiH_i. It is known that f2(2,n)=n+1f_2(2,n)=n+1; in fact, if GG is a graph of order nn, then c(G)+c(G)n+1c(G)+c(\overline G)\geq n+1 with equality iff ω(G)+α(G)=n+1\omega(G)+\alpha(G)=n+1 where ω\omega is the clique number and α\alpha the independence number. In this paper we investigate fr(t,n)f_r(t,n) when r>2r>2 or t>2t>2. We also characterize graphs GG of order nn with c(G)+c(G)=n+2c(G)+c(\overline G)=n+2.

Keywords

Cite

@article{arxiv.2309.03083,
  title  = {Factoring complete graphs and hypergraphs into factors with few maximal cliques},
  author = {Paul Erdős and David P. Galvin and Fred Galvin and Michael M. Krieger},
  journal= {arXiv preprint arXiv:2309.03083},
  year   = {2023}
}

Comments

22 pages

R2 v1 2026-06-28T12:14:23.501Z