Investigation of infrared singularities in quantum electrodynamics by means of Feynman diagrams

Feynman diagrams are used to show that the infrared divergences factorize when explicit allowance is made for the adiabatic hypothesis and the renormalization procedure. The infrared singularities of the matrix element for annihilation of an electron and a positron into two photons are studied in all perturbation orders. The higher radiative corrections to the cross section of this process in the nonrelativistic case and at high energies are calculated.