A class of marginal deformations of four-dimensional N = 4 super Yang-Mills theory has been found to correspond to a set of smooth, multiparameter deformations of the S 5 target subspace in the holographic dual on AdS 5 × S 5 . We present here an analogous set of deformations that act on global toroidal isometries in the AdS 5 subspace. Remarkably, certain sectors of the string theory remain classically integrable in this larger class of so-called γ-deformed AdS 5 × S 5 backgrounds.Relying on studies of deformed su(2) γ models, we formulate a local sl(2) γ Lax representation that admits a classical, thermodynamic Bethe equation (based on the Riemann-Hilbert interpretation of Bethe's ansatz) encoding the spectrum in the deformed AdS 5 geometry. This result is extended to a set of discretized, asymptotic Bethe equations for the twisted string theory. Near-pp-wave energy spectra within sl(2) γ and su(2) γ sectors provide a useful and stringent test of such equations, demonstrating the reliability of this technology in a wider class of string backgrounds. In addition, we study a twisted Hubbard model that yields certain predictions of the dual β-deformed gauge theory.
IntroductionIn [1], Lunin and Maldacena used an SL(3, R) deformation of AdS 5 × S 5 to find a supergravity solution dual to a class of marginal deformations (known as Leigh-Strassler [2] or β-deformations) of N = 4 super Yang-Mills (SYM) theory. This provided an interesting opportunity to study the AdS/CFT correspondence [3][4][5] in new gravity backgrounds with less supersymmetry. In the case of real deformations, one obtains the gravity dual of a oneparameter family of N = 1 conformal gauge theories, and this particular example has been the focus of many recent investigations: pp-wave limits were studied in [6,7], for example, and other interesting string systems were examined in [8][9][10][11][12][13][14].The notion of the Lunin-Maldacena deformation was generalized by Frolov [15] by considering a sequence of T-dualities and coordinate shifts, or TsT deformations, acting on global toroidal isometries in S 5 . By parameterizing each TsT deformation with separateγ i (i ∈ 1, 2, 3), one generically obtains a non-supersymmetric theory, dual to a non-supersymmetric deformation of N = 4 SYM. 1 (Adhering to conventions in the literature, we will use the symbolsγ i to indicate deformation parameters that naturally appear in the background geometry.) This construction can be extended to include complex deformations by including SL(2, R) transformations. By studying string theory on AdS 5 backgrounds with TsTdeformed S 5 factors, Frolov was also able to demonstrate that bosonic string solutions in these backgrounds can be generated by imposing twisted boundary conditions on known solutions in the undeformed AdS 5 × S 5 geometry. The full action for Green-Schwarz strings in TsT-deformed backgrounds was subsequently constructed in [16], where it was shown that superstring solutions in such backgrounds are again mapped (in a one-to-one fashion) from solutions in t...