Spacetime Quantum Reference Frames and superpositions of proper times

• URL: http://arxiv.org/abs/2101.11628v2
• Date: Sat, 17 Jul 2021 13:08:35 GMT
• Title: Spacetime Quantum Reference Frames and superpositions of proper times
• Authors: Flaminia Giacomini
• Abstract summary: We introduce the notion of a spacetime QRF, associated to a quantum particle in spacetime. We observe a quantum superposition of gravitational redshifts and a quantum superposition of special-relativistic time dilations in the QRF.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: In general relativity, the description of spacetime relies on idealised rods and clocks, which identify a reference frame. In any concrete scenario, reference frames are associated to physical systems, which are ultimately quantum in nature. A relativistic description of the laws of physics hence needs to take into account such quantum reference frames (QRFs), through which spacetime can be given an operational meaning. Here, we introduce the notion of a spacetime QRF, associated to a quantum particle in spacetime. Such formulation has the advantage of treating space and time on equal footing, and of describing the dynamical evolution of a set of quantum systems from the perspective of another quantum system, where the evolution parameter coincides with the proper time of the particle taken as the QRF. Crucially, the proper times in two different QRFs are not related by a standard transformation, but they might be in a quantum superposition. Concretely, we consider N relativistic quantum particles in a weak gravitational field and introduce a timeless formulation in which the global state of the N particles appears "frozen", but the dynamical evolution is recovered in terms of relational quantities. The position and momentum Hilbert space of the particles is used to fix the QRF via a transformation to the local frame of the particle such that the metric is locally inertial at the origin of the QRF. The internal Hilbert space corresponds to the clock space, keeping the proper time in the local frame of the particle. This fully relational construction shows how the remaining particles evolve from the perspective of the QRF and includes the Page-Wootters mechanism for non interacting clocks when the external degrees of freedom are neglected. Finally, we observe a quantum superposition of gravitational redshifts and a quantum superposition of special-relativistic time dilations in the QRF.

Related papers

• Looking for Carroll particles in two time spacetime [55.2480439325792]
  Carroll particles with a non-vanishing value of energy are described in the framework of two time physics. We construct the quantum theory of such a particle using an unexpected correspondence between our parametrization and that obtained by Bars for the hydrogen atom in 1999.
  arXiv  Detail & Related papers  (2023-10-29T15:51:41Z)
• Quantum Reference Frames for Lorentz Symmetry [0.0]
  We introduce a reformulation of relativistic quantum mechanics independent of any notion of preferred temporal slicing. We define transformations that switch between the perspectives of different relativistic QRFs. We analyse two effects, superposition of time dilations and superposition of length contractions, that arise only if the reference frames exhibit both relativistic and quantum-mechanical features.
  arXiv  Detail & Related papers  (2022-12-28T20:04:22Z)
• Quantum superpositions of Minkowski spacetime [0.0]
  "Spacetime superpositions" are quantum superpositions of different spacetimes not related by a global coordinate transformation. We consider the quantum-gravitational effects produced by superpositions of periodically identified Minkowski spacetime. We show that the detector's response exhibits discontinuous resonances at rational ratios of the superposed periodic length scale.
  arXiv  Detail & Related papers  (2022-08-25T13:31:05Z)
• Quantum conformal symmetries for spacetimes in superposition [0.0]
  We build 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. 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.
  arXiv  Detail & Related papers  (2022-06-30T18:00:02Z)
• Localized non-relativistic quantum systems in curved spacetimes: a general characterization of particle detector models [0.0]
  We provide a consistent way of describing a localized non-relativistic quantum system undergoing a timelike trajectory in a curved spacetime. This framework naturally provides a recipe for mapping a quantum theory defined in a non-relativistic background to a theory around a timelike trajectory in curved spacetimes. We then apply our formalism to particle detector models, that is, to the case where the non-relativistic quantum system is coupled to a quantum field in a curved background.
  arXiv  Detail & Related papers  (2022-06-02T18:00:31Z)
• Quantum dynamics corresponding to chaotic BKL scenario [62.997667081978825]
  Quantization smears the gravitational singularity avoiding its localization in the configuration space. Results suggest that the generic singularity of general relativity can be avoided at quantum level.
  arXiv  Detail & Related papers  (2022-04-24T13:32:45Z)
• Quantum time dilation in a gravitational field [39.58317527488534]
  We investigate how the superposition principle affects the gravitational time dilation observed by a simple clock. We show that the emission rate of an atom prepared in a coherent superposition of separated wave packets in a gravitational field is different from the emission rate of an atom in a classical mixture of these packets.
  arXiv  Detail & Related papers  (2022-04-22T10:02:21Z)
• Time and Evolution in Quantum and Classical Cosmology [68.8204255655161]
  We show that it is neither necessary nor sufficient for the Poisson bracket between the time variable and the super-Hamiltonian to be equal to unity in all of the phase space. We also discuss the question of switching between different internal times as well as the Montevideo interpretation of quantum theory.
  arXiv  Detail & Related papers  (2021-07-02T09:17:55Z)
• On the Problem of Time(s) in Quantum Mechanics and Quantum Gravity: recent integrating developments and outlook [0.0]
  How to restore time is the Problem of Time(s) It introduces an intrinsic time property tau associated with the mass of the system. It invalidates Pauli's objection to the existence of a time operator.
  arXiv  Detail & Related papers  (2021-04-20T17:51:05Z)
• Quantum particle across Grushin singularity [77.34726150561087]
  We study the phenomenon of transmission across the singularity that separates the two half-cylinders. All the local realisations of the free (Laplace-Beltrami) quantum Hamiltonian are examined as non-equivalent protocols of transmission/reflection. This allows to comprehend the distinguished status of the so-called bridging' transmission protocol previously identified in the literature.
  arXiv  Detail & Related papers  (2020-11-27T12:53:23Z)
• Projection evolution and quantum spacetime [68.8204255655161]
  We discuss the problem of time in quantum mechanics. An idea of construction of a quantum spacetime as a special set of the allowed states is presented. An example of a structureless quantum Minkowski-like spacetime is also considered.
  arXiv  Detail & Related papers  (2019-10-24T14:54:11Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.