标题： 宇宙学中的奇异超曲面和薄壳 显示英文标题

标题： Singular hypersurfaces and thin shells in cosmology

摘要： 我们分析了球对称几何结构，结合一个宇宙学区域和一个施瓦西黑洞区域，并通过奇异的余维数为1的超曲面连接。在适用于大于三维的一般分析中，假设任意均匀且各向同性的宇宙学模型，我们以宇宙学能量密度的形式推导出超曲面的应力-能量张量。这一分析揭示了一种新颖的精确解，其中包含宇宙学中的辐射以及由无压尘组成的壳层。探索参数空间得到了二十二个不同的解族，包括“宇宙泡沫”和“瑞士奶酪”时空。值得注意的是，具有负宇宙常数的解表现出全息对偶性质。此外，我们还提供了广义相对论中超曲面的教育性介绍以及构建薄壳时空的实际方法。 显示英文摘要

摘要： We analyse spherically symmetric geometries, combining a cosmological patch and a Schwarzschild black hole patch joined via a singular co-dimension 1 hypersurface. In a general analysis applicable to dimensions greater than three, assuming an arbitrary homogeneous and isotropic cosmology, we derive the stress-energy tensor of the hypersurface in terms of the cosmological energy density. This analysis reveals a novel exact solution featuring radiation within the cosmology and a shell composed of pressureless dust. Exploring the parameter space yields twenty-two distinct solution families, including `bubble of cosmology' and `Swiss cheese' spacetimes. Notably, solutions with a negative cosmological constant exhibit a holographic dual. Additionally, we provide a pedagogical introduction to hypersurfaces in general relativity and a practical approach for constructing thin shell spacetimes.