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arXiv · 2512.24421

The Upper Bound of Event Horizon Formation Time in Generalized Oppenheimer-Snyder Collapse

Zhi-Chao Li·H. Khodabakhshi·H. Lu
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Abstract

We prove that, in the framework of the Oppenheimer-Snyder collapse, the Schwarzschild exterior maximizes the event horizon formation time $\Delta T_{\text{eh}}=\frac{19}{6}m$ among all asymptotically flat, static, spherically-symmetric black holes with the same ADM mass $m$ that satisfy the weak energy condition. This bound extends the typical black hole inequalities--such as the Penrose inequality, which constrains spatial geometry--to temporal setting.

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Zhi-Chao Li, H. Khodabakhshi, H. Lu. 2025-12-30. The Upper Bound of Event Horizon Formation Time in Generalized Oppenheimer-Snyder Collapse. https://arxiv.org/abs/2512.24421

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