Hiding dynamical reduction in existing interactions
Collapse models propose an ad hoc albeit working way to solve the measurement problem in quantum mechanics. The price to pay is a fundamental modifications of the dynamics and an empirical deviation from orthodox quantum mechanics. Such a deviation is sometimes put on the credit of gravity because all the other forces are already accounted for in the Standard model. Our objective is to show that this need not be the case. Provided the Markovianity assumption is dropped, it is possible to construct collapse models that have exactly the same empirical content as a purely quantum interacting theory (i.e. with different state vector dynamics, but the same average predictions). As a result, genuine collapse models can be fully hidden within existing interactions. This suggests a possible shift in the understanding of collapse models: as stochastic reformulations of quantum theory rather than as modifications. Further, once applied to QFT, this approach provides natural candidates for relativistic collapse models.