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Related papers: Classical gravity cannot mediate entanglement

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Two very similar proposals have been made recently for witnessing nonclassical features of gravity, by Bose et al. and by Marletto and Vedral. However, while these proposals are asserted to be very general, they are in fact based on a very…

Quantum Physics · Physics 2018-01-31 Michael J. W. Hall , Marcel Reginatto

Observation of gravitationally induced quantum entanglement is often interpreted as a direct evidence of non-classical gravity. While the form and the degree of non-classicality have been rigorously studied from a foundational perspective,…

Quantum Physics · Physics 2026-05-21 Samuel Schlegel , Ankit Kumar , Tomasz Paterek , Borivoje Dakić

A direct quantization of the Newtonian interaction between two masses is known to establish entanglement, which if detected would witness the quantum nature of the gravitational field. Gravitational interaction is yet compatible also with…

An experimental test of quantum effects in gravity has recently been proposed, where the ability of the gravitational field to entangle two masses is used as a witness of its quantum nature. The key idea is that if gravity can generate…

Quantum Physics · Physics 2018-08-08 Chiara Marletto , Vlatko Vedral

Due to the weakness of gravitational coupling, all quantum experiments up to date in which gravity plays a role utilized the field of the Earth. Since this field undergoes practically undetectable back-action from quantum particles, it…

Quantum Physics · Physics 2024-05-16 Ankit Kumar

Ever since gravity-induced entanglement (GIE) experiments have been proposed as a witness of the quantum nature of gravity, more and more theories of classical gravity coupled to quantum matter have been shown to predict GIE, despite the…

General Relativity and Quantum Cosmology · Physics 2026-04-02 Andrea Di Biagio

This is a comment on articles Phys. Rev. Lett. 119, 240401 (2017) [arXiv:1707.06050] and Phys. Rev. Lett. 119, 240402 (2017) [arXiv:1707.06036]. We argue that gravity-induced entanglement by Newtonian forces is agnostic to the quantum or…

Quantum Physics · Physics 2019-01-11 C. Anastopoulos , Bei-Lok Hu

One of the great challenges for 21st century physics is to quantize gravity and generate a theory that will unify gravity with the other three fundamental forces of nature. This paper takes the (heretical) point of view that gravity may be…

General Relativity and Quantum Cosmology · Physics 2009-04-17 Stephen Boughn

Observable signatures of the quantum nature of gravity at low energies have recently emerged as a promising new research field. One prominent avenue is to test for gravitationally induced entanglement between two mesoscopic masses prepared…

Quantum Physics · Physics 2023-02-16 Vasileios Fragkos , Michael Kopp , Igor Pikovski

It is a matter of ongoing discussion whether quantum states can become entangled while only interacting via a classical mediator. This lively debate is deeply interwoven with the question of whether entanglement studies can prove the…

Quantum Physics · Physics 2026-01-30 Sebastian Ulbricht , Andrés Darío Bermúdez Manjarres , Marcel Reginatto

I argue that it is possible for a theory to be neither quantized nor classical. We should therefore give up the assumption that the fundamental theory which describes gravity at shortest distances must either be quantized, or quantization…

General Relativity and Quantum Cosmology · Physics 2012-12-04 Sabine Hossenfelder

The quantum nature of gravity remains experimentally unverified, despite recent proposals to probe it using tabletop experiments such as gravity-mediated entanglement schemes. In parallel, consistent formulations of classical--quantum…

Quantum Physics · Physics 2026-04-09 Shogo Tomizuka , Hiroki Takeda

In view of the enormous difficulties we seem to face in quantizing general relativity, we should perhaps consider the possibility that gravity is a fundamentally classical interaction. Theoretical arguments against such mixed…

General Relativity and Quantum Cosmology · Physics 2010-04-28 S. Carlip

It is shown that a unified description of classical and `quantum mechanical' gravity in its linearized form is possible.

General Physics · Physics 2018-05-18 Partha Ghose

We numerically analyze the dynamical generation of quantum entanglement in a system of 2 interacting particles, started in a coherent separable state, for decreasing values of $\hbar$. As $\hbar\to 0$ the entanglement entropy, computed at…

Quantum Physics · Physics 2015-05-30 Giulio Casati , Italo Guarneri , Jose Reslen

An elementary prediction of the quantization of the gravitational field is that the Newtonian interaction can entangle pairs of massive objects. Conversely, in models of gravity in which the field is not quantized, the gravitational…

Quantum Physics · Physics 2026-05-15 Giuseppe Fabiano , Tomohiro Fujita , Akira Matsumura , Daniel Carney

Classical systems can be entangled. Entanglement is defined by coincidence correlations. Quantum entanglement experiments can be mimicked by a mechanical system with a single conserved variable and 77.8% conditional efficiency. Experiments…

Quantum Physics · Physics 2007-05-23 Douglas G. Danforth

We propose an experiment to test the non-classicality of the gravitational interaction. We consider two optomechanical systems that are perfectly isolated, except for a weak gravitational coupling. If a suitable resonance condition is…

Quantum Physics · Physics 2026-03-11 Andrea Mari , Stefano Zippilli , David Vitali

Markovian master equations underlie many areas of modern physics and, despite their apparent simplicity, they encode a rich and complex dynamics which is still under active research. We identify a class of continuous variable Markovian…

Quantum Physics · Physics 2026-02-06 Oliviero Angeli , Matteo Carlesso

We show that if a discrete quantum gravity is not classical, then it cannot be generated by an isometric dynamics. In particular, we show that if the quantum measure {\mu} (or equivalently the decoherence functional) is generated by an…

General Relativity and Quantum Cosmology · Physics 2011-12-06 Stan Gudder