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Kantowski-Sachs universe cannot be closed

Xin-zhou Li·Jian-gang Hao
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Abstract

In this paper, by analyzing the instability against spatially homogeneous and anisotropic perturbations of the Kantowski-Sachs-type during different cosmological epoch, we show that it is a theoretical consequence of the general relativity that the KS universe must be open or flat if it underwent the matter dominated and/or radiation dominated era in its past evolution, which theoretically confirms the flatness of our observable universe.

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Xin-zhou Li, Jian-gang Hao. 2003-08-18. Kantowski-Sachs universe cannot be closed. https://doi.org/10.1103/physrevd.68.083512

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