Master integrals for bipartite cuts of three-loop photon self energy

A bstract We calculate the master integrals for bipartite cuts of the three-loop propagator QED diagrams. These master integrals determine the spectral density of the photon self energy. Our results are expressed in terms of the iterated integrals, which, apart from the 4 m cut (the cut of 4 massive lines), reduce to Goncharov’s polylogarithms. The master integrals for 4 m cut have been calculated in our previous paper in terms of the one-fold integrals of harmonic polylogarithms and complete elliptic integrals. We provide the threshold and high-energy asymptotics of the master integrals found, including those for 4 m cut.