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arXiv · 2108.07101

Entropy, Black holes, and the New Cyclic Universe

Anna Ijjas·Paul J. Steinhardt
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Abstract

We track the evolution of entropy and black holes in a cyclic universe that undergoes repeated intervals of expansion followed by slow contraction and a smooth (non-singular) bounce. In this kind of cyclic scenario, there is no big crunch and no chaotic mixmaster behavior. We explain why the entropy following each bounce is naturally partitioned into near-maximal entropy in the matter-radiation sector and near-minimal in the gravitational sector, satisfying the Weyl curvature conditions conjectured to be essential for a cosmology consistent with observations. As a result, this kind of cyclic universe can undergo an unbounded number of cycles in the past and/or the future.

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Anna Ijjas, Paul J. Steinhardt. 2022-05-06. Entropy, Black holes, and the New Cyclic Universe. https://doi.org/10.1016/j.physletb.2021.136823

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