Six-dimensional theories with (2,0) supersymmetry

Sammanfattning: In this thesis the so called (2,0) theories in six dimensions are discussed. These theories are of special interest because they do not contain dynamical gravity despite their high dimensionality. The origin of (2,0) theory in terms of higher-dimensional theories (Type IIB string theory and M-theory) is treated, as well as compactifications of the six-dimensional theory to supersymmetric Yang-Mills theories in five and four dimen- sions. The representations of the (2,0) algebra on a free massless tensor multiplet and on a free tensile string are discussed and actions are derived describing the dynamics of these. Furthermore, the bosonic part of the string is coupled to the bosonic part of the tensor multiplet action; this is then used as a starting point for the supersymmetric coupling of a spinning string to a background consisting of tensor multiplet fields.