Quantum reference frames for spacetime symmetries and large gauge transformations

2025/09/01 by Janssen, Daan W.
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Mathematical Physics (math-ph)

paper · doi:10.48550/arxiv.2509.01458

Abstract

Symmetries are a central concept in our understanding of physics. In quantum theories, a quantum reference frame (QRF) can be used to distinguish between observables related by a symmetry. The framework of operational QRFs provides a means to describe observables in terms of their relation to a reference quantum system. We discuss a number of applications of QRFs in the context of quantum field theory on curved spacetimes: 1) A type reduction result for algebras arising from QFTs and QRFs with good thermal properties. 2) Quantisation of boundary electric fluxes and gluing procedures for quantum electromagnetism on spacetimes with boundaries.

Citations

• Observation of charge-parity symmetry breaking in baryon decays
• Symmetry, Reference Frames, and Relational Quantities in Quantum Mechanics

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