Principle of Relativity and The Perturbative Quantum Gravity

We develop a purely quantum theory based on the novel principle of relativity, termed the quantum principle of relativity, instead of directly applying the diffeomorphism invariance. We demonstrate that the essence of the principle can be extended into the quantum realm, maintaining the identical structures of active and passive transformations. By employing this principle, we show that quantum gravitational effects are naturally realized within the perturbatively valid theory, with general relativity emerging in large distances. We derive graviton propagators and provide several examples grounded in this novel framework.