A note on ensemble holography for rational tori

Understand

We study simple examples of ensemble-averaged holography in free compact boson CFTs with rational values of the radius squared.

• These well-known rational CFTs have an extended chiral algebra generated by three currents.
• We consider the modular average of the vacuum character in these theories, which results in a weighted average over all modular invariants.
• In the simplest case, when the chiral algebra is primitive (in a sense we explain), the weights in this ensemble average are all equal.