# Is the Born Rule Unstable in Quantum Gravity?

### APA

Valentini, A. (2018). Is the Born Rule Unstable in Quantum Gravity?. Perimeter Institute. https://pirsa.org/18020103

### MLA

Valentini, Antony. Is the Born Rule Unstable in Quantum Gravity?. Perimeter Institute, Feb. 15, 2018, https://pirsa.org/18020103

### BibTex

@misc{ pirsa_PIRSA:18020103, doi = {10.48660/18020103}, url = {https://pirsa.org/18020103}, author = {Valentini, Antony}, keywords = {Quantum Gravity}, language = {en}, title = {Is the Born Rule Unstable in Quantum Gravity?}, publisher = {Perimeter Institute}, year = {2018}, month = {feb}, note = {PIRSA:18020103 see, \url{https://pirsa.org}} }

Antony Valentini Clemson University

## Abstract

We argue that in quantum gravity there is no stable equilibrium state corresponding to the Born rule. Our main argument rests on the continued controversy over the physical meaning of the Wheeler-DeWitt equation. We suggest that attempts to interpret it are hampered by the conventional assumption that probabilities should be governed by a fixed Born rule. It is possible to abandon this assumption in a de Broglie-Bohm interpretation. We argue that a stable Born rule emerges only in the limiting Schrödinger regime in which the system is described by an effective (time-dependent) Schrödinger equation with an appropriate conserved current. We consider a regime in which quantum-gravitational corrections to the Schrödinger equation induce a non-conservation of the standard current. Such a regime can be consistently described in de Broglie-Bohm theory. As a result, quantum-gravitational effects can generate non-equilibrium deviations from the Born rule even starting from an initial equilibrium state. We provide estimates for such effects in an inflationary de Sitter background.