Talk 1: Basic properties of CM abelian varieties Abstract: The theory of abelian varieties with complex multiplication is a natural generalization of the theory of CM elliptic curves, but it exhibits a richer structure than can be perceived in the 1-dimensional case. In this expository talk we will explain some basic notions in the theory (such as reflex fields, CM types, and the Shimura-Taniyama formula) and we discuss special features when the ground field is the complex field or a finite field.