Perimeter Institute for Theoretical Physics
Talks by Bianca Dittrich
Euclidean quantum gravity approaches have a long history but suffer from a number of severe issues. This gives a strong motivation to develop Lorentzian approaches. Spin foams constitute an important such approach, which incorporate a rigorously derived discrete area spectrum. I will explain how this discrete area spectrum is connected to the appearance of an anomaly, which explains the significance of the Barbero-Immirzi parameter and forces an extension of the quantum configuration space, to also include torsion degrees of freedom.