Title: The River Model of Gravitational Collapse Show Chinese title

Title: 引力坍缩的河流模型

Abstract: We show that the transformation of a time-evolving spherically symmetric metric tensor into a Painleve-Gullstrand-Lemaitre form brings forth a few curious consequences. The time evolution describes a non-singular gravitational collapse, leading to a bounce and dispersal of all the clustered matter, or a wormhole geometry for certain initial conditions. The null convergence condition is violated only at the onset of bounce or the wormhole formation. As an example, the requirements to develop a Simpson-Visser wormhole/regular black-hole geometry is discussed. The solution can be regarded as a new time-evolving twin of sonic dumb holes found in analog gravity. Show Chinese abstract

Abstract: 我们证明了将一个随时间演化的球对称度规张量转化为Painlevé-Gullstrand-Lemaître形式会带来一些有趣的后果。 该时间演化描述了一种非奇异的引力坍缩，导致反弹和所有聚集物质的分散，或者在某些初始条件下形成虫洞几何结构。 只有在反弹开始或虫洞形成之初，才会违反零能量条件。 作为一个例子，讨论了形成Simpson-Visser虫洞/正则黑洞几何结构的条件。 该解可以被视为类引力中发现的声学哑洞的一种新的随时间演化的双胞胎。