title: Symmetry for Flavor-Kinematics Duality from an Action.
abstract: We propose a new representation of the nonlinear sigma model that exhibits a manifest duality between flavor and kinematics. The fields couple exclusively through cubic Feynman vertices which define the structure constants of an underlying kinematic algebra. The action is invariant under a combination of internal and spacetime symmetries whose conservation equations imply flavor-kinematics duality, ensuring that all Feynman diagrams satisfy kinematic Jacobi identities. Substituting flavor for kinematics, we derive a new cubic action for the special Galileon theory. In this picture, the vanishing soft behavior of amplitudes is a by-product of the Weinberg soft theorem.
authors.affiliation: Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Clifford
authors.initials: C
authors.lastname: Cheung
authors.affiliation: Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Chia-Hsien
authors.initials: CH
authors.lastname: Shen