The N-cosine model--algebraic structures and integrable points on the marginal manifold

We review some algebraic aspects of integrable models in 2 space-time dimensions, such as quantum group and Yangian symmetry. We also discuss the application of perturbed conformal field theory and renormalization group techniques to analyzing the integrability properties of 2 dimensional quantum field theories by probing their underlying algebraic structure. These methods are then used to investigate the integrability of the N-cosine model, a multi-field generalization of the sine-Gordon model, and integrable points are found on a manifold of the parameter space where the interaction becomes marginal