Black Holes and Solitons in String Theory

Abstract

In this review I discuss various aspects of some of the recently constructed black hole and soliton solutions in string theory. I begin with the axionic instanton and related solutions of bosonic and heterotic string theory. The latter ten-dimensional solutions can be compactified to supersymmetric monopole, string and domain wall solutions which break $1/2$ of the spacetime supersymmetries of $N=4, D=4$ heterotic string theory, and which can be generalized to two-parameter charged black hole solutions. The low-energy dynamics of these solutions is also discussed, as well as their connections with strong/weak coupling duality and target space duality in string theory. Finally, new solutions are presented which break $3/4, 7/8$ and all of the spacetime supersymmetries and which also arise in more realistic $N=1$ and $N=2$ compactifications.