| The quest for naturalness has made symmetry breaking a familiar ingredient in physics beyond the Standard Model. In the first half of this work, we present two broad studies of symmetry breaking which are relevant to experiments in the near future. In particular, we consider (1) general deformations of gauge mediated super-symmetry breaking and their associated phenomenologies and (2) an effective field theory which universally characterizes the dynamics of all single field inflation models. The second half of this work addresses more formal aspects of the S-matrix and its fundamental properties. We present (3) a proof of on-shell recursion relations for generic theories, (4) a construction of the spinor-helicity formalism in six dimensions, and (5) a detailed study of the S-matrix in twistor space. |
