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Bouncing unitary cosmology I. Mini-superspace general solution

Research output: Contribution to journalArticle

Original languageEnglish
Article number035009
Number of pages21
JournalClassical and Quantum Gravity
Issue number3
Early online date18 Jan 2019
DateAccepted/In press - 12 Dec 2018
DateE-pub ahead of print - 18 Jan 2019
DatePublished (current) - 18 Jan 2019


We offer a new proposal for cosmic singularity resolution based upon a quantum cosmology with a unitary bounce. This proposal is illustrated via a novel quantization of a mini-superspace model in which there can be superpositions of the cosmological constant. This possibility leads to a finite, bouncing unitary cosmology. Whereas the usual Wheeler-DeWitt cosmology generically displays pathological behaviour in terms of non-finite expectation values and non-unitary dynamics, the finiteness and unitarity of our model are formally guaranteed. For classically singular models with a massless scalar field and cosmological constant, we show that well-behaved quantum observables can be constructed and generic solutions to the universal Schrödinger equation are singularity-free. Generic solutions of our model displays novel features including: (i) superpositions of values of the cosmological constant; (ii) universal effective physics due to non-trivial self-adjoint extensions of the Hamiltonian; and (iii) bound 'Efimov universe' states for negative cosmological constant. The last feature provides a new platform for quantum simulation of the early universe. A companion paper provides detailed interpretation and analysis of particular cosmological solutions that display a cosmic bounce due to quantum gravitational effects, a well-defined FLRW limit far from the bounce, and a semi-classical turnaround point in the dynamics of the scalar field which resembles an effective inflationary epoch.

    Structured keywords

  • Centre for Science and Philosophy

    Research areas

  • bouncing cosmology, cosmological constant, problem of time, quantum cosmology, singularity resolution



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    Rights statement: This is the author accepted manuscript (AAM). The final published version (version of record) is available online via IOP at . Please refer to any applicable terms of use of the publisher.

    Accepted author manuscript, 718 KB, PDF document

    Licence: CC BY-NC-ND



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