String Universality for Permutation Orbifolds

Understand

The hypothesis that every theory of quantum gravity in AdS_3 is a dimensional reduction of string/M-theory leads to a natural conjecture for the density of states of two dimensional CFTs with a large central charge limit.

• We prove this conjecture for 2D CFTs which are orbifolds by permutation groups.
• In particular, we characterize those permutation groups which give CFTs with well-defined large N limits and can thus serve as holographic duals to bulk gravity theories in AdS_3.
• We then show that the holographic dual of a permutation orbifold will have a Hagedorn spectrum in the large N limit.