Speaker
Christoph Dlapa
(DESY)
Description
I present work which provides evidence through two loops that rational
letters of polylogarithmic Feynman integrals are captured by the Landau
equations, when the latter are recast as a polynomial of the kinematic
variables of the integral, known as the principal A-determinant.
Focusing on one loop, I further discuss how all square-root letters may
also be obtained, by re-factorizing the principal A-determinant with
the help of Jacobi identities. The letters are verified by explicitly
constructing canonical differential equations for the one-loop
integrals in both odd and even dimensions of loop momenta.
