https://doi.org/10.1140/epjc/s10052-024-12621-z
Regular Article - Theoretical Physics
Geodesically complete cyclic cosmologies and entropy
1
Institute for Cosmology and Philosophy of Nature, Trg svetog Florijana 16, Križevci, Croatia
2
Department of Physics, Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, 10 000, Zagreb, Croatia
Received:
14
September
2023
Accepted:
25
February
2024
Published online:
8
March
2024
We demonstrate that there exists a class of cyclic cosmological models, such that these models can in principle solve the problem of the entropy growth, and are at the same time geodesically complete. We thus show that some recently stated conclusions, according to which cyclic cosmologies solving the problem of entropy growth can not be geodesically complete due to the Borde–Guth–Vilenkin (BGV) theorem, are not justified. We also add a short conceptual discussion on entropy and cyclic cosmology, and present a detailed analysis of entropy density growth during periodic and non-periodic evolution for cyclic cosmologies.
© The Author(s) 2024
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