AdS cycles in eternally inflating background

Understand

In the eternally inflating background, the bubbles with AdS vacua will crunch.

• However, this crunch might be followed by a bounce.
• It is generally thought that the bubble universe may be cyclic, which will go through a sequence of AdS crunches, until the field inside bubble finally lands at a dS minimum.
• However, we show that due to the amplification of field fluctuation, the bubble universe going through AdS cycles will inevitably fragment within two or three cycles.