Room 326

Classical eikonal from Magnus expansion

Adarsh Vishwakarma

IMSc

I will present the paper arxiv:2410.22988v3. S-matrix can be expanded into a series called Magnus expansion. Unlike the Dyson series, the Magnus expansion is built with nested commutators. This enables a straightforward classical limit through Dirac's correspondence without entailing any superclassical terms which the KMOC formalism is plagued with. The classical limit of the expansion has a diagrammatic representation in terms of oriented trees. I will talk about the three methods to carry out the expansion: using equation of motion, the Magnus expansion and using hopf algebra to efficiently calculate the coefficients of the diagrams.