Dr. Christoph Chiaffrino (HU Berlin)

Title: A string field theory inspired regularization of point-particle QFT

Abstract:

String field theory vertices are regularized by stubs. These are tubes/strips representing the propagation of external string states into a vertex. I will use this idea to systematically regularize BV-quantized point particle QFTs. As an example, I will apply this to (vector + axial) QED. We will find a family of regularized actions (parametrized by a stub parameter) that is gauge invariant to all orders. I use this family to compute the axial anomaly as an obstruction to a solution to the quantum master equation. I will also show how these actions are related to each other via canonical transformations on the space of BV fields/anti-fields. This ensures that all actions are physically equivalent.