The seeds of EFT double copy

A bstract We explore the double copy of effective field theories (EFTs), in recently proposed generalized color-kinematics and Kawai-Lewellen-Tye (KLT) approaches. In former, we systematically construct scalar numerators satisfying Jacobi identities from simpler numerator seeds with trace-like permutation properties. This construction has advantage being easily applicable to any multiplicity, which exemplify up 6-point. It employs linear map between color factors formed by single traces generators products structure constants, also relates KLT formalisms, allowing produce kernels at arbitrary order EFT expansion. At 4-point, show that all are generated they only yield double-copy amplitudes can be obtained traditional kernel. perform initial checks suggesting same conclusions hold 5-point. focus on single-trace massless EFTs however control higher-derivative corrections gauge gravity theories.