Taming Dirac strings and timelike loops in vacuum gravity
Taming Dirac strings and timelike loops in vacuum gravity
复制标题
驯服真空重力中的狄拉克弦和类时环
DOI：
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发表时间：
2019
影响因子：
5
通讯作者：
Sandipan Sengupta
中科院分区：
文献类型：
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作者：
Suvikranth Gera;Sandipan Sengupta
本文分析了纯重力经典解中与狄拉克弦和闭合类时曲线有关的奇点问题。首先针对Taub-NUT几何结构，介绍并建立了一种消除这些问题的方法。这被一阶场方程的光滑解所取代，一阶场方程被定义为Taub宇宙到简并度规阶段的唯一扩展。作为一个额外的特征，这个框架自然地在没有物质的引力理论的背景下提供了对磁荷的几何解释。最后，利用度规行列式的两个阶段，我们也找到了Misner几何的(平滑和唯一的)延续，消除了存在于其爱因斯坦表现形式中的封闭的类似时间的世界线。
The problem of singularities associated with Dirac strings and closed timelike curves in classical solutions of pure gravity is analyzed here. A method to eliminate these is introduced and established first for the Taub-NUT geometry. This is superceded by a smooth solution of first order field equations, which is defined to be a unique extension of the Taub Universe to a degenerate metric phase. As an additional feature, this framework naturally provides a geometric interpretation of the magnetic charge in the context of gravity theory without matter. Finally, exploiting the two phases of the metric determinant, we find a (smooth and unique) continuation of the Misner geometry as well, ridding it of closed timelike worldlines which exist in its otherwise Einsteinian manifestation.