Strings and Particles in Six Dimensions - A perturbative approach to (2,0) theory

Abstract: In this thesis we give a brief review of the six-dimensional (2,0) theories and how they emerge from the study of string/M-theory. In particular, the A_N version of (2,0) theory is the world-volume theory of N+1 parallel M5-branes in the limit where gravity decouples. We suggest a perturbative approach to these theories and describe the relevant degrees of freedom from a six-dimensional perspective. A certain model is investigated, consisting of tensile self-dual strings interacting with massless tensor multiplet particles in six-dimensional Minkowski spacetime. We argue that this model should describe the A_1 version of (2,0) theory far away from the superconformal fixed point. The appended research papers are all more or less connected to this model and the remainder of the introductory text summarizes the most important results from these publications. More specifically, we give a supersymmetric and kappa-symmetric action describing a tensile self-dual string coupled to an on-shell tensor multiplet background. We then show how this action can be used to study scattering of tensor multiplet particles against a string. Finally, we discuss the conjecture that (2,0) theory should constitute the ultra-violet completion to five-dimensional maximally supersymmetric Yang-Mills theory.