On calculations within the nonlinear sigma model

The chiral SU(N) nonlinear sigma model represents one of the simplest case of effective field theory. For the last several decades it has played an extremely important role not only for the low energy phenomenology but also in many other areas of theoretical physics. In this talk we will focus on the tree-level scattering amplitudes of the n-Goldstone bosons. It will be shown that it can be reconstructed using the BCFW-like recursion relations. This method, which does not rely on the Lagrangian description, is much more efficient than the standard Feynman diagram techniques. (paper)