PhD Defense by Andreas Helset

This thesis is devoted to theoretical developments in effective field theories and scattering amplitudes. 

We discuss several effective field theories, ranging from the effective-field-theory extension of the Standard Model to an effective field theory describing gravitational interactions of black holes. We also develop modern methods for calculating scattering amplitudes, and apply them to effective field theories.

Quantum field theory successfully describes many different phenomena, ranging in scale from the shortest scales we can experimentally probe at the Large Hadron Collider, to the scales of black hole mergers. Many of the quantum field theories which describe the observed phenomena are effective field theories. Improving our calculational abilities of the effective field theories is of great value, both practically and theoretically. Modern methods have been developed which enable many calculations which were previously intractable with traditional methods. One of the main objectives of this thesis is to apply the ever-increasing toolbox of modern methods for calculating scattering amplitudes to effective field theories. This would simultaneously improve our ability to perform hard calculations as well as illuminate the underlying structure of the effective field theory.


    Participating via Zoom by following link: https://ucph-ku.zoom.us/j/62510334390?pwd=RElNU21CQVpSWitZbENTRDM0VXR2UT09