mgr Artur Pietrykowski

The "Unique Effective Action" and charge renormalization in Higher-derivative Quantum Gravity

The Background Field Method proved very useful in quantization of theories with a gauge symmetry. It allows for construction of manifestly ovariant perturbation series. The main object that enables for this construction is the Effective Action. It accounts for the back-reaction of a quantum processes on the classical background. However these quantum corrections to the classical quantities are derived from the off-shell effective action, which is gauge and parametrization dependent. In this talk the construction of a gauge and parametrization independent "Unique Effective Action" will be presented. As an application of this formalism the gravitational correction to running gauge coupling for the Maxwell field in the framework of Higher-derivative Quantum Gravity will be presented.