Divergent Integrals of QED in Krein Space Quantization

The usual quantum field theory leads to an ultraviolet divergence in the vacuum energies and an infrared divergence in the two-point functions. It has been shown that the presence of unphysical negative-frequency states (Krein space quantization) plays the role of an automatic renormalization tool for the theory of quantized fields. In the standard QED, the divergent quantities are found in the self-energy, vacuum polarization, and vertex graphs. It seems as if evaluating divergent integrals of QED in Krein space leads to convergent values.