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On the "Causality Argument" in Bouncing Cosmologies

Jerome Martin·Patrick Peter
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Abstract

We exhibit a situation in which cosmological perturbations of astrophysical relevance propagating through a bounce are affected in a scale-dependent way. Involving only the evolution of a scalar field in a closed universe described by general relativity, the model is consistent with causality. Such a specific counter-example leads to the conclusion that imposing causality is not sufficient to determine the spectrum of perturbations after a bounce provided it is known before. We discuss consequences of this result for string motivated scenarios.

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Jerome Martin, Patrick Peter. 2003-12-18. On the "Causality Argument" in Bouncing Cosmologies. https://doi.org/10.1103/physrevlett.92.061301

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