Mass-Singularity Structure of QED and Perturbative Quantum Gravity Scatterings

Abstract: In this thesis, the mass singularities occurring in the cross-section of electron scattering processes are investigated. Two types of scatterings are studied: Quantum Electrodynamics (QED) scatterings, and Perturbative Quantum Gravity (PQG) scatterings. We show how mass singularities in QED and PQG cancel when real and virtual diagrams are included in the scattering cross-section. We find that in both theories, the scattering cross-section is infrared (IR) finite and that IR singularities are regulated by the finite energy resolution of the detector. Finally, the differences in the eikonal factorization and the mass singularity structure in QED and PQG are studied. From this, some important properties of PQGare inferred and discussed.