Automorphisms and Periods of Cubic Fourfolds

Cubic fourfold plays a central role in algebraic geometry because of its close relation to hyper-Kahler geometry. In this talk I will start with this relation and discuss the Hodge theory and moduli theory for cubic fourfolds. Then I will introduce an application of the above theories, namely, a complete classification of the symplectic automorphism groups of smooth cubic fourfolds. This work can be regarded as a higher dimensional analogue of Mukai's celebrated result on classification of finite symplectic automorphism groups of K3 surfaces. This is a joint work with Radu Laza.