Oberseminar SoSe 2012 Zusammenfassung des Vortrags von Hisanori Ohashi, (Nagoya Universitiy, Japan)
On automorphisms of K3 surfaces and Enriques surfaces
Recent abundant researches on K3 surfaces seem to have activated studies on Enriques surfaces, too. In 1986 Kondo classified Enriques surfaces with finite automorphism group Aut(S). In the talk I want to discuss a little more general question, "What finite subgroups of Aut(S) appear when S varies among Enriques surfaces?" The corresponding question for K3 surfaces was considered by Nikulin and Mukai in '80s. In the talk I will introduce two partial classification results for Enriques surfaces: one is for involutions (joint with H. Ito) and the other for Mathieu automorphisms (joint with S. Mukai).