PHYSICAL REVIEW D, cilt.81, sa.8, 2010 (SCI-Expanded)
If general relativity is an emergent phenomenon, there may be small violations of diffeomorphism invariance. We propose a phenomenology of perturbatively small violations of general relativity by the inclusion of terms which break general covariance. These can be tested by matching to the parameterized post-Newtonian formalism. The most sensitive tests involve pulsar timing and provide an extremely strong bound, with a dimensionless constraint of order 10(-20) relative to gravitational strength.