Scattering in topologically massive gravity, chiral gravity, and the corresponding anyon-anyon potential energy

We compute the tree-level scattering amplitude between two covariantly conserved sources in generic cosmological topologically massive gravity augmented with a Fierz-Pauli term that has three massive degrees of freedom. We consider the chiral gravity limit in the anti-de Sitter space as well as the limit of flat-space chiral gravity. We show that chiral gravity cannot be unitarily deformed with a Fierz-Pauli mass. We calculate the nonrelativistic potential energy between two point-like spinning sources. In addition to the expected mass-mass and spin-spin interactions, there are mass-spin interactions due to the presence of the gravitational Chern-Simons term which induces spin for any massive object and turns it to an anyon. We also show that the tree-level scattering is trivial for the flat-space chiral gravity.