随时间变化的球对称时空中的视界奇点、能量条件与阴影
Horizon singularity, energy conditions and shadows in time-dependent and spherically symmetric spacetime
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中文总结 AI 辅助
本文研究随时间变化的球对称时空，发现静态虫洞转为动力学虫洞通常会出现奇点，可构造无奇点动力学虫洞，分析其能量条件，模拟其光学外观演化并提出可通过光子环测量其时间演化。
中文摘要 AI 辅助
本文分析了一些描述超致密天体的动力学时空解。研究表明，将描述单向虫洞的静态时空转化为随时间变化的动力学时空时，通常会出现奇点。对多个著名的虫洞解进行研究后发现，当这些虫洞解被推广为随时间变化的虫洞时，会变为奇异的。不过，本文证明可以构造出无奇点的动力学虫洞，并基于无鬼场的双标量场模型重构了支撑这类动力学时空的相应拉格朗日量。此外，还分析了能量条件，发现动力学奇异虫洞仍可满足能量条件。最后，对这类动力学天体的光学外观演化进行了模拟，并与静态解进行了比较，出现了一些有趣的特征，这为通过观测天体周围的光子环结构来测量动力学天体的时间演化提供了途径。
英文摘要
Some dynamical spacetime solutions that describe ultra-compact objects are analysed. We show that by turning a static spacetime that describes a one-way wormhole into a dynamical time-dependent one, a singularity might arise in general. Several well-known wormhole solutions are studied, which are shown to become singular when promoted to a time-dependent wormhole. However, we show that one can construct a dynamical wormhole free of singularities. The corresponding Lagrangian that holds such dynamical spacetimes is also reconstructed, based on a two-scalar-field model free of ghosts. Energy conditions are also analysed, which might remain satisfied for a dynamical -singular- wormhole. Finally, the evolution of the optical appearance of such dynamical objects is simulated and compared to static solutions. Some interesting features emerge that point to a way to measure the time evolution of dynamical objects by looking at the photon ring structure around the object.
