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Quantum-to-classical transition for fluctuations in the early Universe

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arxiv gr-qc/9802003 v1 pith:V6NK3L6R submitted 1998-02-02 gr-qc astro-phhep-thquant-ph

classification gr-qcastro-phhep-thquant-ph
keywords universequantumearlyinhomogeneitiesperturbationstransitionbasisclassical
verification ladder T0 review T1 audit T2 compute T3 formal
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According to the inflationary scenario for the very early Universe, all inhomogeneities in the Universe are of genuine quantum origin. On the other hand, looking at these inhomogeneities and measuring them, clearly no specific quantum mechanical properties are observed. We show how the transition from their inherent quantum gravitational nature to classical behaviour comes about -- a transition whereby none of the successful quantitative predictions of the inflationary scenario for the present-day universe is changed. This is made possible by two properties. First, the quantum state for the spacetime metric perturbations produced by quantum gravitational effects in the early Universe becomes very special (highly squeezed) as a result of the expansion of the Universe (as long as the wavelength of the perturbations exceeds the Hubble radius). Second, decoherence through the environment distinguishes the field amplitude basis as being the pointer basis. This renders the perturbations presently indistinguishable from stochastic classical inhomogeneities.

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Cited by 14 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

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