Seminarium Teorii Względności i Grawitacji

We have recently developed a new understanding of probability in quantum gravity. In this talk we provide an overview of this new approach and its implications. Adopting the pilot-wave formulation of quantum physics, we argue that there is no Born rule at the fundamental level of quantum gravity with a non-normalisable Wheeler-DeWitt wave function. Instead, the universe is in a perpetual state of ‘quantum nonequilibrium’. Dynamical relaxation to the Born rule can occur only after the early universe has emerged into a semiclassical or Schrödinger approximation, with a time-dependent and normalisable wave function. We also show that quantum-gravitational corrections to the Schrödinger approximation can generate tiny deviations from the Born rule. The possibility of observing these effects is discussed. [Reference: A. Valentini, Beyond the Born rule in quantum gravity, Found. Phys. 53, 6 (2023).] Broadcast in room 1.40