English

The $r$-matching sequencibility of complete graphs

Combinatorics 2018-11-15 v3

Abstract

Alspach [ Bull. Inst. Combin. Appl., 52 (2008), pp. 7-20] defined the maximal matching sequencibility of a graph GG, denoted ms(G)ms(G), to be the largest integer ss for which there is an ordering of the edges of GG such that every ss consecutive edges form a matching. Alspach also proved that ms(Kn)=n12ms(K_n) = \bigl\lfloor\frac{n-1}{2}\bigr\rfloor. Brualdi et al. [ Australas. J. Combin., 53 (2012), pp. 245-256] extended the definition to cyclic matching sequencibility of a graph GG, denoted cms(G)cms(G), which allows cyclical orderings and proved that cms(Kn)=n22cms(K_n) = \bigl\lfloor\frac{n-2}{2}\bigr\rfloor. In this paper, we generalise these definitions to require that every ss consecutive edges form a subgraph where every vertex has degree at most r1r\geq 1, and we denote the maximum such number for a graph GG by msr(G)ms_r(G) and cmsr(G)cms_r(G) for the non-cyclic and cyclic cases, respectively. We conjecture that msr(Kn)=rn12ms_r(K_n) = \bigl\lfloor\frac{rn-1}{2}\bigr\rfloor and rn121 cmsr(Kn)rn12{\bigl\lfloor\frac{rn-1}{2}\bigr\rfloor-1}~ \leq cms_r(K_n) \leq \bigl\lfloor\frac{rn-1}{2}\bigr\rfloor and that both bounds are attained for some rr and nn. We prove these conjectured identities for the majority of cases, by defining and characterising selected decompositions of KnK_n. We also provide bounds on msr(G)ms_r(G) and cmsr(G)cms_r(G) as well as results on hypergraph analogues of msr(G)ms_r(G) and cmsr(G)cms_r(G).

Keywords

Cite

@article{arxiv.1711.05013,
  title  = {The $r$-matching sequencibility of complete graphs},
  author = {Adam Mammoliti},
  journal= {arXiv preprint arXiv:1711.05013},
  year   = {2018}
}
R2 v1 2026-06-22T22:45:19.354Z