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arXiv · 2507.06385

A Breathing Universe is Consistent

Samuel Blitz
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Abstract

We consider a toy FRW universe with the exotic topology $S^1 \times S^3$. We show that for a specific choice of quantum field content, the semi-classical Friedman equations are consistent with temporal periodicity as required by the $S^1$ timelike factor. A straightforward consequence is that entropy reversals occur during each cycle, consistent with Hawking's proposed connection between the thermodynamic and cosmological arrows of time.

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Samuel Blitz. 2025-07-08. A Breathing Universe is Consistent. https://doi.org/10.1088/1361-6382%2Fae6c8d

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