New families of atomic Latin squares and perfect one-factorisations

A perfect 1-factorisation of a graph G is a decomposition of G into edge disjoint 1-factors such that the union of any two of the factors is a Hamiltonian cycle. Let p\geq 11 be prime. We demonstrate the existence of two non-isomorphic perfect 1-factorisations of Kp+1 (one of which is well-known) and five non-isomorphic perfect 1-factorisations of Kp,p. If 2 is a primitive root modulo p then we show the existence of eleven non-isomorphic perfect 1-factorisations of Kp,p and five main classes of atomic Latin squares of order p. Only three of these main classes were previously known. One of the two new main classes has a trivial autotopy group.
Last modified: Tue Sep 7 19:06:43 EST 2004