Should we necessarily treat masses as localized when analysing tests of quantum gravity?

• URL: http://arxiv.org/abs/2405.20514v1
• Date: Thu, 30 May 2024 22:17:08 GMT
• Title: Should we necessarily treat masses as localized when analysing tests of quantum gravity?
• Authors: Adrian Kent,
• Abstract summary: Recently proposed table-top tests of quantum gravity'' involve creating, separating and recombining superpositions of masses at non-relativistic speeds. Analyses suggest that negligible gravitational radiation is generated if the interference experiments involve sufficiently small accelerations.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Recently proposed ``table-top tests of quantum gravity'' involve creating, separating and recombining superpositions of masses at non-relativistic speeds. The general expectation is that these generate superpositions of gravitational fields via the Newtonian potential. Analyses suggest that negligible gravitational radiation is generated if the interference experiments involve sufficiently small accelerations. One way of thinking about this is that matter and the static gravitational field are temporarily entangled and then disentangled. Another is that the static gravitational field degrees of freedom are dependent on the matter and do not belong to a separate Hilbert space, and that there is always negligible entanglement between matter and dynamical gravitational degrees of freedom. In this last picture, localized masses effectively become infinitely extended objects, inseparable from their Newtonian potentials. While this picture seems hard to extend to a fully relativistic theory of non-quantum gravity, it has significant implications for analyses of how or whether BMV and other non-relativistic experiments might test the quantum nature of gravity. If the masses in a BMV experiment are regarded as occupying overlapping regions (or indeed all of space), explaining how they become entangled does not require that their gravitational interaction involves quantum information exchange. On this view, while the experiments test gravity in a regime where quantum theory describes all relevant matter degrees of freedom, they do not necessarily test its quantum nature. It might be argued that no plausible explanation other than quantum gravity could be consistent both with these experiments and with relativity. But this relies on further theoretical assumptions and is weaker than claiming direct evidence for quantum gravitational interactions from the experiments alone.

Related papers

• Table-top nanodiamond interferometer enabling quantum gravity tests [34.82692226532414]
  We present a feasibility study for a table-top nanodiamond-based interferometer. By relying on quantum superpositions of steady massive objects our interferometer may allow exploiting just small-range electromagnetic fields.
  arXiv  Detail & Related papers  (2024-05-31T17:20:59Z)
• Quantum effects in gravity beyond the Newton potential from a delocalised quantum source [1.1111141727030245]
  We show for the first time that gravity is not compatible with a classical description. Experiments such as the generation of gravitationally induced entanglement between two quantum sources of gravity can be explained with the Newton potential.
  arXiv  Detail & Related papers  (2024-02-15T19:33:04Z)
• Detecting Gravitationally Interacting Dark Matter with Quantum Interference [51.38773840176434]
  We show that there is a theoretical possibility to directly detect such particles using highly sensitive gravity-mediated quantum phase shifts. In particular, we consider a protocol utilizing Josephson junctions.
  arXiv  Detail & Related papers  (2023-09-15T08:22:46Z)
• Testing the Braneworld Theory with Identical Particles [41.94295877935867]
  braneworld scenarios postulate that the spacetime we effectively observe is actually a 4-dimensional brane embedded in a higher-dimensional spacetime. We propose an experimental test that uses a pair of gravitationally interacting identical particles to determine the validity of certain braneworld models.
  arXiv  Detail & Related papers  (2023-09-06T16:40:12Z)
• Testing the nonclassicality of gravity with the field of a single delocalized mass [55.2480439325792]
  A setup is proposed that is based on a single delocalized mass coupled to a harmonically trapped test mass. We investigate the in-principle feasibility of such an experiment, which turns out to crucially depend on the ability to tame Casimir-Polder forces.
  arXiv  Detail & Related papers  (2023-07-18T15:40:16Z)
• Does the Universe have its own mass? [62.997667081978825]
  The mass of the universe is a distribution of non-zero values of gravitational constraints. A formulation of the Euclidean quantum theory of gravity is also proposed to determine the initial state. Being unrelated to ordinary matter, the distribution of its own mass affects the geometry of space.
  arXiv  Detail & Related papers  (2022-12-23T22:01:32Z)
• Inference of gravitational field superposition from quantum measurements [1.7246954941200043]
  In non-relativistic quantum mechanics, the gravitational field in such experiments can be written as a superposition state. We empirically demonstrate that alternative theories of gravity can avoid gravitational superposition states. Proposed experiments with superposed gravitational sources would provide even stronger evidence that gravity is nonclassical.
  arXiv  Detail & Related papers  (2022-09-06T04:37:07Z)
• Is gravitational entanglement evidence for the quantization of spacetime? [0.0]
  Experiments witnessing the entanglement between two particles interacting only via the gravitational field have been proposed as a test whether gravity must be quantized. We present a parametrized model for the gravitational interaction of quantum matter on a classical spacetime, inspired by the de Broglie-Bohm formulation of quantum mechanics.
  arXiv  Detail & Related papers  (2022-05-02T14:37:24Z)
• Can we detect the quantum nature of weak gravitational fields? [0.0]
  An experimental answer to the question of the quantization of gravity is of renewed interest in the era of gravitational wave detectors. We review and investigate an important subset of quantum gravity, detecting quantum signatures of weak gravitational fields in table-top experiments and interferometers.
  arXiv  Detail & Related papers  (2021-10-06T07:21:09Z)
• Gravitational effects in macroscopic quantum systems: a first-principles analysis [0.0]
  We analyze the weak-field limit of General Relativity with matter and its possible quantisations. This analysis aims towards a predictive quantum theory to provide a first-principles description of gravitational effects in macroscopic quantum systems.
  arXiv  Detail & Related papers  (2021-03-14T21:29:11Z)
• Atom-interferometric test of the universality of gravitational redshift and free fall [48.82541018696971]
  Light-pulse atom interferometers constitute powerful quantum sensors for inertial forces. We present a specific geometry which together with state transitions leads to a scheme that is sensitive to both violations of the universality of free fall and gravitational redshift.
  arXiv  Detail & Related papers  (2020-01-27T13:35:30Z)

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.