Arithmetic and Attractors

We study relations between some topics in number theory and supersymmetric black holes. These relations are based on the “attractor mechanism” of N = 2 supergravity. In IIB string compactification this mechanism singles out certain “attractor varieties.” We show that these attractor varieties are constructed from products of elliptic curves with complex multiplication for N = 4, 8 compactifications. The heterotic dual theories are related to rational conformal field theories. In the case of N = 4 theories U -duality inequivalent backgrounds with the same horizon area are counted by the class number of a quadratic imaginary field. The attractor varieties are defined over fields closely related to class fields of the quadratic imaginary field. We discuss some extensions to more general Calabi-Yau compactifications and explore further connections to arithmetic including connections to Kronecker’s Jugendtraum and the theory of modular heights. The paper also includes a short review of the attractor mechanism. A much shorter version of the paper summarizing the main points is the companion note entitled “Attractors and Arithmetic,” hep-th/9807056.