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arXiv · 2402.00694

Multiway Junction Conditions: Booklets and Webs

Jia-Yin Shen·Cheng Peng·Li-Xin Li
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Abstract

Junction conditions play a crucial role in constructing new gravity solutions. In this paper, we derive the junction condition for gluing together an arbitrary number of spacetimes along a common interface. We develop a geometric technique of reverse extension and provide precise definitions of geometric quantities at the interface. This leads to a geometric derivation of the multiway junction condition. As a cross-check, we independently re-derive the junction condition by varying the action of some specific gravitational models including both Einstein gravity and dilaton gravity. We demonstrate that the junction condition is invariant under a change of frames, and the form of the junction condition is the same for both spacelike and timelike interfaces.

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Jia-Yin Shen, Cheng Peng, Li-Xin Li. 2024-02-01. Multiway Junction Conditions: Booklets and Webs. https://doi.org/10.1103/physrevd.110.066021

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