Spin frames vs spin structures: A framework for Dirac fields in interaction with gravity

Lorenzo Fatibene, University of Torino

We relax spin structures to discuss Dirac fields in interaction with gravity and their conservation laws. That is an example of a more general framework, called gauge natural field theories, which accommodates theories which are generally covariant and they have an additional gauge symmetry. The framework is geometrically expressed and it accommodates a geometric formulation of both variational calculus and conservation laws. We shall also briefly compare with other frameworks such as the double cover of frame bundles.

MC 5479