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The thin string limit of Cosmic Strings coupled to gravity

K R P Sjodin·J A Vickers
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Abstract

The thin string limit of Cosmic Strings is investigated using a description in terms of Colombeau's theory of nonlinear generalised functions. It is shown that in this description the energy-momentum tensor has a well defined thin string limit. Furthermore the deficit angle of the conical spacetime that one obtains in the limit may be given in terms of the distributional energy-momentum tensor. On the other hand it is only in the special case of critical coupling that the energy-momentum tensor defined in the Colombeau algebra is associated to a conventional distribution. The asymptotics of both the matter and gravitational field are investigated in the thin string limit and it is shown how this leads to the `conical approximation' which is valid outside the inner core of the string.

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K R P Sjodin, J A Vickers. 2001-08-02. The thin string limit of Cosmic Strings coupled to gravity. https://arxiv.org/abs/gr-qc/0108009

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