北京雁栖湖应用数学研究院

皮奥特·赫鲁谢尔 , 普斯卡尔·蒙达尔 , 赵博文

普斯卡尔·蒙达尔

2026年03月25日 16:30 至 17:30

A3-3-201

Zoom 442 374 5045 (BIMSA)

We prove that a marginally outer trapped surface (MOTS) can form as a result of Einsteinian evolution in pure vacuum spacetime starting from regular initial data free of MOTSs due to pure boundary effects. We adapt a Cauchy-double-null framework and use the boundary generalized mean curvature condition for the existence of an interior MOTS imposed by the author S-T Yau. In particular, we prove that the condition of Yau can be met dynamically starting from a configuration that does not verify the same through a focusing mechanism. In fact, a very mild incoming radiation can cause a large enough generalized boundary mean curvature of an isotropically large domain so that a MOTS exists in the interior. This is fundamentally different from black hole formation by standard “gravitational collapse" and can be interpreted as the dynamical realization of a long-suspected idea in GR: MOTS can form because of “global geometry", not just quasi-local concentration of gravity/matter. This is a joint work with Prof. S-T Yau.

Puskar Mondal is currently an assistant professor in BIMSA. He's been a fellow and lecturer at Harvard CMSA of Mathematics (his mentor is Prof. Shing-Tung Yau), and was a Ph.D. student at Yale University, under the supervision of Prof. Vincent Moncrief.