Description
Abstract: It has recently been argued that AdS/CFT states describing closed universes fail to admit a conventional large-N limit due to large fluctuations. Motivated by this, I re-examine the double-cone wormhole, a well-understood saddle contributing to the spectral form factor. The spectral form factor has similar fluctuations in the late-time regime where the double cone controls the semiclassical answer, obstructing a large-N limit. I then analyze correlations between theories at different values of N in general one-cut matrix models and in higher-dimensional AdS/CFT examples, and assess when an average over N in the CFT can (and cannot) reproduce the semiclassical double-cone contribution.