On circulant ternary coherent configurations of prime degree

Abstract: Ternary coherent configurations are, on the one hand, a special case of multidimensional coherent configurations introduced by L. Babai (2016), and, on the other hand, a natural generalization of association schemes on triples introduced by D. M. Mesner and P. Bhattacharya (1990). A ternary coherent configuration X is said to be circulant if the automorphism group Aut(X) of X has a regular cyclic subgroup, and schurian if the classes of X are the orbits of the componentwise action of the group Aut(X) on triples of points of X. It is proved that any circulant ternary coherent configuration X of prime degree p is schurian with the possible exception of the case when X is an association schemes on triples and either Aut(X) = AGL1(p) and p = +1, or -1 (mod 8), or Aut(X) is a proper subgrou of AGL1(p).