tensor in certain gapped three-dimensional field theories, and show that at zero momentum,
the parity-odd part in both of these correlation functions is one-loop exact. In particular, we
find a new and simplified derivation of the Coleman-Hill theorem that also clarifies several
subtleties in the original argument. For the energy momentum tensor, our result means that
the gravitational Chern-Simons term for the background metric does not receive quantum …