QED vertex form factors at two loops

We present the closed analytic expression of the form factors of the two-loop QED vertex amplitude for on-shell electrons of finite mass m and arbitrary momentum transfer S=-Q2. The calculation is carried out within the continuous D-dimensional regularization scheme, with a single continuous parameter D, the dimension of the space-time, which regularizes at the same time ultraviolet (UV) and infrared (IR) divergences. The results are expressed in terms of 1-dimensional harmonic poly logarithms of maximum weight 4