AI 中文总结
该研究探讨嵌入五维带电AdS时空的壳世界宇宙演化，发现其非奇异弹跳可化解柯西视界不稳定性，引入体中长弦后弹跳仍存在且规避该不稳定性。
AI 中文摘要
我们研究嵌入五维带电AdS体时空的球形膜在壳世界（暗泡）场景下的宇宙学演化。当膜宇宙学常数为零或取小值时，壳世界宇宙具有非奇异的弹跳与循环特性，该弹跳由体时空的电荷参数诱导；当膜宇宙学常数取大值时，壳世界经历非奇异弹跳并永恒膨胀。在特定条件下，膜在体视界外弹跳，可几何化解决标准膜世界模型中存在的柯西视界不稳定性。此外，对线性标量微扰的分析表明，测试标量场模式在弹跳过程中保持正则且不发散。最后，我们在体中引入均匀分布的长弦，证明弹跳仍会持续且可规避视界不稳定性。
英文摘要
We investigate the cosmological evolution of a spherical brane within the shellworld (dark bubble) scenario embedded in a five-dimensional charged AdS bulk spacetime. For zero or small value of the brane cosmological constant, the shellworld universe has a nonsingular bouncing and cyclic nature with the bounce induced by the charge parameter of the bulk spacetime. On large value of the brane cosmological constant, the shellworld undergoes a nonsingular bounce and expands eternally. Under certain conditions, the brane bounces outside the bulk horizons, leading to a geometrical resolution of the Cauchy horizon instability present in standard braneworld models. Furthermore, analysis of linear scalar perturbations reveals that test scalar field modes remain regular and non-divergent across the bounce. Finally, we incorporate uniformly distributed long strings in the bulk and demonstrate that the bounce still persists while avoiding the horizon instability.
Comments13 pages and 7 figures
