Einstein-Cartan Theory and Gauge Symmetry
arXiv:1212.3266
Abstract
We argue that the non gauge invariant coupling between torsion and the Maxwell or Yang-Mills fields in Einstein-Cartan theory can not be ignored. Arguments based in the existence of normal frames in neighbourhoods, and an approximation to a δ-function, lead to gauge invariant observables.
Replacement of eq.(8) in v1 by equations (5)-(9) in v2