Effective Lagrangians for Scalar Fields and Finite Size Effects in Field   Theory
  We discuss the approach of effective field theory on a d-dimensional Euclidean space in a scalar theory with two different mass scales in the presence of flat surfaces. Then considering Dirichlet and Neumann boundary conditions, we implement the renormalization program in the lambda phi^{4} theory in a region bounded by two parallel hyperplanes in the one-loop approximation. 
M. I. Caicedo and N. F. Svaiter