Tomorrow morning (9am GMT) I am giving a seminar in Novosibirsk (virtually of course). The abstract is below. If you are interested in attending let me know I will give you the Zoom link.

Title: Nonschurian primitive association schemes with many automorphisms

Abstract: This talk is about primitive coherent configurations of degree with more than automorphisms, for constant . Babai conjectured that all such are so-called Cameron schemes, the orbital configurations of large primitive groups for . We will describe several families of examples that show Babai’s conjecture is actually wrong, strictly interpretted. In particular there is a primitive association scheme of degree for any such that is imprimitive and . But a slightly revised form of Babai’s conjecture is still plausible.