# Pancyclic arcs and connectivity in tournaments

1 MASCOTTE - Algorithms, simulation, combinatorics and optimization for telecommunications
CRISAM - Inria Sophia Antipolis - Méditerranée , Laboratoire I3S - COMRED - COMmunications, Réseaux, systèmes Embarqués et Distribués
Abstract : A tournament is an orientation of the edges of a complete graph. An arc is pancyclic in a digraph D if it is contained in a cycle of length l, for every $3\leq l\leq |D|$. In [4], Moon showed that every strong tournament contains at least three pancyclics arcs and characterized the tournaments with exactly three pancyclic arcs. All these tournaments are not 2-strong. In this paper, we are interested in the minimum number $p_k(n)$ of pancyclic arcs in a k-strong tournament of order n. We conjecture that (for $k\geq 2$) there exists a constant $\alpha_k>0$ such that $p_k(n)\geq \alpha_kn$. After proving that every 2-strong tournament has a hamiltonian cycle containing at least five pancyclic arcs, we deduce that for $k\geq 2$, $p_k(n)\geq 2k+3$. We then characterize the tournaments having exactly four pancyclic arcs and those having exactly five pancyclic arcs.
Keywords :
Document type :
Reports
Domain :

Cited literature [1 references]

https://hal.inria.fr/inria-00072210
Contributor : Rapport de Recherche Inria <>
Submitted on : Tuesday, May 23, 2006 - 8:05:39 PM
Last modification on : Monday, October 12, 2020 - 10:30:21 AM
Long-term archiving on: : Sunday, April 4, 2010 - 9:05:00 PM

### Identifiers

• HAL Id : inria-00072210, version 1

### Citation

Frédéric Havet. Pancyclic arcs and connectivity in tournaments. RR-4378, INRIA. 2002. ⟨inria-00072210⟩

Record views