Year: 2024
Type: article
Abstract: Without a complete theory of quantum gravity, the question of how quantum fields and quantum particles behave in a superposition of spacetimes seems beyond the reach of theoretical and experimental investigations. Here we use an extension of the quantum reference frame formalism to address this question for the Klein-Gordon field residing on a superposition of conformally equivalent metrics. Based on the group structure of “quantum conformal transformations'', we construct an explicit quantum operator that can map states describing a quantum field on a superposition of spacetimes to states representing a quantum field with a superposition of masses on a Minkowski background. This constitutes an extended symmetry principle, namely invariance under quantum conformal transformations. The latter allows to build an understanding of superpositions of diffeomorphically non-equivalent spacetimes by relating them to a more intuitive superposition of quantum fields on curved spacetime. Furthermore, it can be used to import the phenomenon of particle production in curved spacetime to its conformally equivalent counterpart, thus revealing new features in modified Minkowski spacetime.
Source: Quantum
Language: English
Subfield: Statistical and Nonlinear Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $215
Funders: National Science Foundation, John Templeton Foundation, Foundational Questions Institute, National Centres of Competence in Research SwissMAP, European Commission, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Österreichischen Akademie der Wissenschaften, Austrian Science Fund, Eidgenössische Technische Hochschule Zürich
Awards: Information-theoretic limits to time measurements, G2708791133, G2831308664, G3170016737, G3984144614, G437809000, G4465348434, G4530899125, G5082131548, G5896890105, Testing the Large-Scale Limit of Quantum Mechanics, Geschwisterlichkeit als Liebesmodell bei Jean Paul, Adalbert Stifter und in intertextuellen Aktualisierungen., The Quantum Information Structure of Spacetime (QISS)
OpenAlex ID: W4404996944