AdS cycles in eternally inflating background

TL;DR

This paper investigates the fate of AdS bubbles in eternal inflation, showing that field fluctuations cause bubble fragmentation within a few cycles, challenging the cyclic universe scenario.

Contribution

It demonstrates that AdS bubble universes fragment after only a few cycles due to amplified field fluctuations, contradicting the idea of a stable cyclic universe.

Findings

AdS bubbles fragment within two or three cycles.

Field fluctuations are amplified during AdS cycles.

Implications for the eternal inflation scenario are discussed.

Abstract

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. We discuss its implication to the eternal inflation scenario.