K3 surfaces with maximal finite automorphism groups

Abstract: In the 80's Nikulin classified all the finite abelian groups acting symplectically on a K3 surface and his results inspired an intensive study of automorphism groups of K3 surfaces. It was shown by Mukai that the maximum order of a finite group acting symplectically on a K3 surface is 960 and that the group is isomorphic to the Mathieu group $M_{20}$. Then Kondo showed that the maximum order of a finite group acting on a K3 surface is 3840 and this group contains the Mathieu group with index four. Kondo showed also that there is a unique K3 surface on which this group acts, which is a Kummer surface. I will present recent results on finite groups acting on K3 surfaces, that contain strictly the Mathieu group and I will classify them. I will show that there are exactly three groups and three K3 surfaces with this property. This is a joint work with C. Bonnafé.

algebraic geometrynumber theory

Audience: researchers in the topic

“Algebraic geometry and arithmetic” Viacheslav Nikulin’s 70th birthday conference

Series comments: The conference is dedicated to the 70th birthday of our colleague and friend Viacheslav Nikulin, who made a huge contribution to the theory of K3 surfaces and also other domains of geometry and arithmetic, including reflection groups, automorphic forms and infinite-dimensional Lie algebras. Topics of the conference reflect mathematical interests of the hero of the day.