Constructing the six-dimensional (2,0) theories

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 then describe the degrees of freedom from a six-dimensional perspective and discuss how to approach these theories. A certain model, consisting of tensile self-dual strings interacting with massless particles described by a (2,0) tensor multiplet in six dimensions, is investigated. We argue that this model should describe the A_1 version of (2,0) theory away from the origin of the moduli space. This model has been the topic of the three appended research papers, and the remainder of the introductory text summarizes the most important results from these publications. More specifically, we give an action describing the bosonic fields of the tensor multiplet interacting with a bosonic string. We then discuss how it should be modified in order to include fermionic fields as well as spinning strings in a supersymmetric fashion. Finally, we give the supersymmetric and kappa-symmetric action for a spinning string coupled to an on-shell tensor multiplet background.