Some Properties of Type I' String Theory

The T-dual formulation of Type I superstring theory, sometimes called Type I' theory, has a number of interesting features. Here we review some of them including the role of D0-branes and D8-branes in controlling possible gauge symmetry enhancement.Comment: 10 pages; Submitted to a volume in memory of Yuri Golfand; v2: reference adde

Some Recent Progress in AdS/CFT

Much of modern string theory research concerns AdS/CFT duality, or more generally, gauge/gravity duality. The main subjects are a) Testing and understanding such dualities by exploring how they work for systems with a lot of supersymmetry b) Constructing and exploring approximate string theory duals of QCD c) Applying gauge/gravity duality to other areas of physics such as condensed matter and nuclear physics. I will briefly discuss the first topic.Comment: 13 pages; Contribution to the proceedings of a symposium celebrating the 80th birthday of Murray Gell-Man

The Generalized Stieltjes Transform and Its Inverse

The generalized Stieltjes transform (GST) is an integral transform that depends on a parameter $\rho > 0$. In previous work a convenient form of the inverse transformation was derived for the case $\rho = 3/2$. This paper generalizes that result to all $\rho > 0$. It is a well-known fact that the GST can be formulated as an iterated Laplace transform, and that therefore its inverse can be expressed as an iterated inverse Laplace transform. The form of the inverse transform derived here is a one-dimensional integral that is considerably simpler.Comment: 11 pages, 1 figur

Recent Progress in AdS/CFT

The study of AdS/CFT (or gauge/gravity) duality has been one of the most active and illuminating areas of research in string theory over the past decade. The scope of its relevance and the insights it is providing seem to be ever expanding. In this talk I briefly describe some of the attempts to explore how the duality works for maximally supersymmetric systems.Comment: 11 page

The future of string theory

Prophesy is just for fun. The more useful purpose of the exercise is to identify important issues and to stimulate thought about where they stand and how they might be resolved. The subject areas that are fair game include all of particle physics and cosmology