In this paper, we study the collapse of a thin dust shell from the point of view of the horizon dynamics. We identify the critical surfaces at which time and space coordinates interchange their roles and investigate their properties by using the formalism of trapped surfaces. We show the existence of marginally outer trapped surfaces that are associated with the presence of quasi-local horizons. A particular shell configuration that avoids the formation of horizons is interpreted as naked shell.

中文翻译：

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黑壳和裸壳

在本文中，我们从视界动力学的角度研究了薄尘壳的坍塌。我们通过使用被困表面的形式来确定时间和空间坐标交换它们的角色并研究它们的属性的关键表面。我们展示了与准局部视界的存在相关的边缘外圈的存在。避免形成层位的特定壳配置被解释为裸壳。