标题： 无奇点的引力坍缩：从常规黑洞到无视界物体 显示英文标题

标题： Singularity-free gravitational collapse: From regular black holes to horizonless objects

摘要： 彭罗斯奇点定理表明，如果在引力坍缩中形成一个被困区域，那么该区域内必须形成奇点。 然而，人们普遍认为，量子引力效应应该可以避免奇点的出现。 在这里，我们将探讨在引力坍缩中避免奇点的最低要求，并且不依赖于特定的量子引力模型，讨论与这种时空结构正则化相关可能的正则时空。 特别是，我们将揭示正则黑洞、黑洞反弹及其相应无视界物体极限之间的紧密而相当微妙的关系。 在此过程中，我们将特别关注那些位于有视界和无视界几何边界上的临界（极端）黑洞配置。 虽然这些研究是在静态配置中进行的，但普遍存在的一般性不稳定性强烈表明需要考虑更现实的时间依赖的动力学时空。 由于缺乏具体的动力学模型，对于演化的几何结构很难做出更严格的陈述。 尽管如此，我们仍将在这里总结目前的理解，并讨论它们对未来现象学研究的含义。 显示英文摘要

摘要： Penrose's singularity theorem implies that if a trapped region forms in a gravitational collapse, then a singularity must form as well within such region. However, it is widely expected that singularities should be generically avoided by quantum gravitational effects. Here we shall explore both the minimum requirements to avoid singularities in a gravitational collapse as well as discuss, without relying on a specific quantum gravity model, the possible regular spacetimes associated to such regularization of the spacetime fabric. In particular, we shall expose the intimate and quite subtle relationship between regular black holes, black bounces and their corresponding horizonless object limits. In doing so, we shall devote specific attention to those critical (extremal) black hole configurations lying at the boundary between horizonful and horizonless geometries. While these studies are carried out in stationary configurations, the presence of generic instabilities strongly suggest the need for considering more realistic time-dependent dynamical spacetimes. Missing specific dynamical models, much less rigorous statements can be made for evolving geometries. We shall nonetheless summarize here their present understanding and discuss their implications for future phenomenological studies.