Spin, Statistics, Spacetime and Quantum Gravity

We explore the possibility that the connection between spin and statistics in quantum physics is of dynamical origin. We suggest that the gravitational field could provide a fully local mechanism for the phase that arises when fermionic and bosonic particles are exchanged. Our results hold even if the symmetry of space and time is Galilean, thus establishing that special relativity is not needed to explain the existence of spin (although it does motivate the introduction of creation and annihilation of particles, but this is a separate issue). We provide a model for the coupling between a particle of general spin and the gravitational field and discuss it within the context of both the equivalence principle and the Sagnac effect. This leads us to present a new experiment for testing the quantum nature of the gravitational field.