Locally covariant chiral fermions and anomalies
  We define chiral fermions in the presence of non-trivial gravitational and gauge background fields in the framework of locally covariant field theory. This allows to straightforwardly compute the chiral anomalies on non-compact Lorentzian space-times, without recourse to a weak field approximation. 
Jochen Zahn
hep-th gr-qc math-ph math.MP