Finite size effects in integrable quantum field theory: the sine-Gordon   model with boundaries
  In this thesis we review recent progresses on Nonlinear Integral Equation approach to finite size effects in two dimensional integrable quantum field theory with boundaries, with emphasis to sine-Gordon model with Dirichlet boundary conditions. Exact calculations of the dependence of the energy spectrum on the size and on boundary conditions are presented for vacuum and many excited states. 
Marco Bellacosa (Bologna University)