On string theory on deformed BTZ and TT̄

A bstract Aspects of superstring theory on deformed BTZ black holes, formed near k NS5 branes by p fundamental strings, and single-trace TT̄ T T ¯ holography, are presented. The excitation energy of a singly wound long string plus its contribution to the energy of the black hole, 1 /p fraction of the black-hole energy, is the same as that in TT̄ T T ¯ deformed CFT 2 with c = 6 k . This supports the claim that the black hole can be thought of as a state in a symmetric product of p CFT 2 ’s of central charge 6 k , where the black-hole energy is split equally among all p factors. A comment on superstring theory on deformed global AdS 3 is also presented.