In field theory, the "double copy" can be thought of as a multiplicative map between tree amplitudes of two field theories into tree amplitudes of another theory. This map has an identity element that is closely linked to the multiplication kernel that defines the KLT formulation of the double-copy. The kernel ensures that the result of the product of color-ordered tree amplitude results in an amplitude of a local theory: for example, it ensures the cancelation of unphysical double-poles and it supplies missing poles. From a bottom-up EFT perspective, such properties place constraints on generalizations of the double copy, such as higher-derivative corrections. We explore these constraints and formulate a program to bootstrap the double-copy kernel from the bottom-up using the KLT algebra. This results in a generalized double-copy for EFTs and an interesting question is from such a bottom-up approach, what makes the KLT string theory kernel special? In the talk, I'll describe these ideas and give examples of applications.
If you’re free and interested, there will also be an informal discussion ~10 minutes after the seminar held.