Finite size effects in perturbed boundary conformal field theories
  We discuss the finite-size properties of a simple integrable quantum field theory in 1+1 dimensions with non-trivial boundary conditions. Novel off-critical identities between cylinder partition functions of models with differing boundary conditions are derived. 
P. Dorey, M. Pillin, A. Pocklington, I. Runkel, R. Tateo and G.M.T.   Watts