Is quantum gravity necessary?

By Steven Carlip. 2008

295 citations recorded by the source corpus.

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 classical–quantum models are strong, but not conclusive, and the question is ultimately one for experiment. I review some work in progress on the possibility of experimental tests, exploiting the nonlinearity of the classical–quantum coupling, which could help settle this question.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/3f3b4cf203b6b3ca21f88358867a5bae529d5d0d

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In Astronomy and Astrophysics

In Atomic and Molecular Physics, and Optics

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Citations in the corpus

On the possibility of laboratory evidence for quantum superposition of geometries (2018, background): “The possibility of quantum superposition of geometries is largely given for granted in the quantum gravity research community, but its consequences have never been empirically observed, and is still questioned by isolated voices in the literature (see [8–14] and references therein.”
Tabletop experiments for quantum gravity: a user’s manual (2018, background): “Another early proposal, described by Carlip and Salzmann in 2006, was to look for a loss of coherence in matter-wave Talbot-Lau interferometry [80, 81, 130], and more recently there have been proposals to look for distortions in the energy spectrum of optically trapped nanoparticles [131–133].”
The Schrödinger–Newton equation and its foundations (2014, background): “It has been commented repeatedly that such a theory would be incompatible with established principles of physics [19, 20] but these arguments turn out to be inconclusive [15, 16, 21, 22].”
A Postquantum Theory of Classical Gravity? (2018, unknown): “(34).”
The Schrödinger–Newton equation as a non-relativistic limit of self-gravitating Klein–Gordon and Dirac fields (2012, background): “The interested reader is referred to the book by Kiefer [26] and references therein, and the recent discussion in Carlip [6], and Salzman and Carlip [7].”