Descripción: Recently, exact agreement has been found between bulk and boundary three-point functions in Ad S3 × S3 × T4 with Neveu-Schwarz-Neveu- Schwarz (NSNS) fluxes. This represents a nontrivial check of AdS/CFT correspondence beyond the supergravity approximation as it corresponds to an exact worldsheet computation. When taking a closer look at this computation, one notices that a crucial point for the bulk-boundary agreement to hold is an intriguing mutual cancellation between worldsheet contributions corresponding to the Ad S3 and to the S3 pieces of the geometry, that results in a simple factorized form for the final three-point function. In this note we review this cancellation and clarify some points about the analytic relation between the SU (2) and the SL (2,R) structure constants. In particular, we dicuss the connection to the Coulomb gas representation. We also make some comments on the four-point function. © 2009 American Institute of Physics.

Descripción: We study AdS-waves in the three-dimensional new theory of massive gravity recently proposed by Bergshoeff, Hohm, and Townsend. The general configuration of this type is derived and shown to exhibit different branches, with different asymptotic behaviors. In particular, for the special fine tuning m 2 = 1/(2l 2), solutions with logarithmic fall-off arise, while in the range -1/(2l 2)$">m 2 > -1/(2l 2), spacetimes with Schrödinger isometry group are admitted as solutions. Spacetimes that are asymptotically AdS 3, both for the Brown-Henneaux and for the weakened boundary conditions, are also identified. The metric function that characterizes the profile of the AdS-wave behaves as a massive excitation on the spacetime, with an effective mass given by m eff 2 = m 2-1/(2l 2). For the critical value m 2 = -1/(2l 2), the value of the effective mass precisely saturates the Breitenlohner-Freedman bound for the AdS 3 space where the wave is propagating on. The analogies with the AdS-wave solutions of topologically massive gravity are also discussed. Besides, we consider the coupling of both massive deformations to Einstein gravity and find the exact configurations for the complete theory, discussing all the different branches exhaustively. One of the effects of introducing the Chern-Simons gravitational term is that of breaking the degeneracy in the effective mass of the generic modes of pure New Massive Gravity, producing a fine structure due to parity violation. Another effect is that the zoo of exact logarithmic specimens becomes considerably enlarged. © 2009 SISSA.

Descripción: A recent paper [1] claims that topologically massive gravity contains only chiral boundary excitations at a particular value of the Chern-Simons coupling. On the other hand, propagating bulk degrees of freedom with negative norm were found even at the chiral point in [2]. The two references use very different methods, making comparison of their respective claims difficult. In this letter, we use the method of [1] to construct a tower of physical propagating bulk states satisfying standard AdS boundary conditions. Our states have finite norm, with sign opposite to that of right-moving boundary excitations. Our results thus agree with [2] and disagree with [1]. © 2008 SISSA.