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The Ori-Soen time machine

Ken D. Olum
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Abstract

Ori and Soen have proposed a spacetime which has closed causal curves on the boundary of a region of normal causality, all within a region where the weak energy condition (positive energy density) is satisfied. I analyze the causal structure of this spacetime in some simplified models, show that the Cauchy horizon is compactly generated, and argue that any attempt to build such a spacetime with normal matter might lead to singular behavior where the causality violation would otherwise take place.

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Ken D. Olum. 2000-04-18. The Ori-Soen time machine. https://doi.org/10.1103/physrevd.61.124022

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