Seminar

The ADE Du Val singularities have very many different characterisations, as quotient singularities by finite subgroups G in
SL(2,C), as "simple" singularities in the sense of unfolding, as weighted homogeneous singularities with weights 1/2+1/3+1/5 > 1 (etc.), as singularities with resolution diffeomorphic to their Milnor fibre, and many, many others. They formed the springboard for the study of 3-fold minimal models, and for the Mackay correspondence, and relate to much material that is currently reaching fruition on orbifold cohomology, crepant resolutions, Calabi-Yau geometry and algebra, and much else. I will try to give an informative informal narrative some of the more entertaining adventures of these singularities. The talk is intended in part as service material for Kawamata's seminar at 4:00 pm.