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The metric around a straight, static and infinitely long cosmic string is flat except for the topological deficit in the angular coordinate, as described for example here. As a result, there is no gravitational force on surrounding matter. The deficit angle is also expected to be quite small, of order $10^{-6}$ radians.

My question is: what would happen if such a string was on a collision course with earth ? assuming that it interacts only gravitationally, will it simply pass through? or will there be some observable effect ?

J. Delaney
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1 Answers1

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Interesting question. I found this paper:

Motohashi & Suyama, "Detecting cosmic string passage through the Earth by consequent global earthquake". Astrophys. Space Sci. 348, 565-569 (2013).

which discusses the effects of a cosmic string passing through or near earth. The conclusion is that it will likely generate global earthquake whose magnitude depends on string tension -- from potentially catastrophic, to barely noticeable.

Michael Seifert
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Kosm
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