Lectures on Non Perturbative Field Theory and Quantum Impurity Problems: Part II

These are notes of lectures given at The NATO Advanced Study Institute/EC Summer School on New Theoretical Approaches to Strongly Correlated Systems'' (Newton Institute, April 2000). They are a sequel to the notes I wrote two years ago for the Summer School Topological Aspects of Low Dimensional Systems’', (Les Houches, July 1998). In this second part, I review the form-factors technique and its extension to massless quantum field theories. I then discuss the calculation of correlators in integrable quantum impurity problems, with special emphasis on point contact tunneling in the fractional quantum Hall effect, and the two-state problem of dissipative quantum mechanics.