String theory as a universal language

TL;DR

This paper discusses recent developments and speculations in string theory, including open strings in AdS space, D-branes, higher-dimensional conformal theories, and cosmological constant issues, highlighting its potential as a universal language in physics.

Contribution

It introduces new results and speculations on open strings, D-branes, and higher-dimensional conformal theories, expanding the understanding of string theory's foundational aspects.

Findings

Open strings in AdS space exhibit unique properties.

D-branes display unusual features relevant to string interactions.

Higher-dimensional conformal gauge theories are explored with new insights.

Abstract

This article, based on the Klein lecture, contains some new results and new speculations on various topics. They include discussion of open strings in the AdS space, unusual features of D-branes, conformal gauge theories in higher dimensions. We also comment on the infrared screening of the cosmological constant and on the "brane worlds"