Projects per year
Abstract
We challenge the view that there is a basic conflict between the fundamental principles of Quantum Theory and General Relativity and, in particular, the fact that a superposition of massive bodies would lead to a violation of the Equivalence Principle. It has been argued that this violation implies that such a superposition must inevitably spontaneously collapse (like in the DiósiPenrose model). We identify the origin of such an assertion in the impossibility of finding a local and classical reference frame in which Einstein's Equivalence Principle would hold. In contrast, we argue that the formulation of the Equivalence Principle can be generalized so that it holds for reference frames that are associated with quantum systems in a superposition of spacetimes. The core of this new formulation is the introduction of a quantum diffeomorphism to such Quantum Reference Frames. This procedure reconciles the principle of linear superposition in Quantum Theory with the principle of general covariance and the Equivalence Principle of General Relativity. Hence, it is not necessary to invoke a gravityinduced spontaneous state reduction when a massive body is prepared in a spatial superposition.
Original language  English 

Article number  015601 
Number of pages  5 
Journal  AVS Quantum Science 
Volume  4 
Issue number  1 
Early online date  5 Jan 2022 
DOIs  
Publication status  Published  1 Mar 2022 
Austrian Fields of Science 2012
 103025 Quantum mechanics
 103028 Theory of relativity

Beyond C: Quantum Information Systems Beyond Classical Capabilities
Walther, P., Brukner, C., Briegel, H., Kirchmair, G., Kraus, B., Lechner, W., Monz, T., Weihs, G., Roos, C., Cirac, J. I., Fink, J., Paulovics, V., Dakic, B. & Schuch, N.
1/03/19 → 28/02/27
Project: Research funding
