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arXiv · 2111.02963

Unitarily inequivalent quantum cosmological bouncing models

Jaime de Cabo Martin·Przemysław Małkiewicz·Patrick Peter
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Abstract

By quantising the background as well as the perturbations in a simple one fluid model, we show that there exists an ambiguity in the choice of relevant variables, potentially leading to incompatible observational physical predictions. In a classical or quantum inflationary background, the exact same canonical transformations lead to unique predictions, so the ambiguity we put forward demands a semiclassical background with a sufficiently strong departure from classical evolution. The latter condition happens to be satisfied in bouncing scenarios, which may thus be having predictability issues. Inflationary models could evade such a problem because of the monotonic behavior of their scale factor; they do, however, initiate from a singular state which bouncing scenarios aim at solving.

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Jaime de Cabo Martin, Przemysław Małkiewicz, Patrick Peter. 2021-11-04. Unitarily inequivalent quantum cosmological bouncing models. https://doi.org/10.1103/physrevd.105.023522

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