English

Row-Hamiltonian Latin squares and Falconer varieties

Combinatorics 2023-12-21 v1

Abstract

A \emph{Latin square} is a matrix of symbols such that each symbol occurs exactly once in each row and column. A Latin square LL is \emph{row-Hamiltonian} if the permutation induced by each pair of distinct rows of LL is a full cycle permutation. Row-Hamiltonian Latin squares are equivalent to perfect 11-factorisations of complete bipartite graphs. For the first time, we exhibit a family of Latin squares that are row-Hamiltonian and also achieve precisely one of the related properties of being column-Hamiltonian or symbol-Hamiltonian. This family allows us to construct non-trivial, anti-associative, isotopically LL-closed loop varieties, solving an open problem posed by Falconer in 1970.

Keywords

Cite

@article{arxiv.2211.13826,
  title  = {Row-Hamiltonian Latin squares and Falconer varieties},
  author = {Jack Allsop and Ian M. Wanless},
  journal= {arXiv preprint arXiv:2211.13826},
  year   = {2023}
}