Integrable Quantum Field Theories, in the Bulk and with a Boundary

Abstract

This thesis considers massive field theories in 1+1 dimensions known as affine Toda quantum field theories. We first consider the boundary sine-Gordon model, deriving a complete picture of the boundary bound state structure for general integrable boundary conditions, and then more general ATFTs in the bulk, discovering a "generalised bootstrap" equation which explicitly encodes the Lie algebra into the S-matrix. This last is related to a number of S-matrix identities, as well as a generalisation of the idea that the conserved charges of the theory form an eigenvector of the Cartan matrix.