TT¯TT̄ and LST

It was recently shown that the theory obtained by deforming a general two dimensional conformal theory by the irrelevant operator TT̄ is solvable. In the context of holography, a large class of such theories can be obtained by studying string theory on AdS 3. We show that a certain single trace TT̄ deformation of the boundary CFT 2 gives rise in the bulk to string theory in a background that interpolates between AdS 3 in the IR and a linear dilaton spacetime in the UV, i.e. to a two dimensional vacuum of Little String Theory. This construction provides holographic duals for a large class of vacua of string theory in asymptotically linear dilaton spacetimes, and sheds light on the UV behavior of TT̄ deformed CFT 2. It may provide a step towards holography in flat spacetime.