Related papers: Closed Strings and Moduli in $AdS_3/CFT_2$

String theory on NS-NS AdS_3 x S^3 admits an exactly marginal deformation which breaks the SL(2,R)_R x SL(2,R)_L isometry of AdS_3 down to SL(2,R)_R x U(1)_L. The holographic dual is an exotic and only partially understood type of…

We continue our study of the worldsheet theory of superstrings on $\mathrm{AdS}_3 \times \mathrm{S}^3 \times \mathbb{T}^4$ in the tensionless limit arXiv:1911.00378. We consider the theory on higher genus surfaces. We give evidence that the…

We exhibit a simple class of exactly marginal "double-trace" deformations of two dimensional CFTs which have AdS_3 duals, in which the deformation is given by a product of left and right-moving U(1) currents. In this special case the…

These lecture notes, based on the course given at IPhT in November/December 2023, provide a pedagogical introduction to the study of strings in AdS$_3$ backgrounds supported by NSNS flux from the worldsheet perspective, including a number…

For the purpose of better understanding the AdS/CFT correspondence it is useful to have a description of the theory for all values of the 't Hooft coupling, and for all $N$. We discuss such a description in the framework of Matrix theory…

We consider worldsheet string theory on $Z_N$ orbifolds of $AdS_3$ associated with conical singularities. If the orbifold action includes a similar twist of $S^3$, supersymmetry is preserved, and there is a moduli space of vacua arising…

In this PhD thesis we review some aspects of integrable models related to string backgrounds or their deformations. In the first part we develop methods to obtain exact results in the AdS3/CFT2 correspondence. We consider the AdS_3 x S^3 x…

We study finite temperature string scale $AdS_3$ backgrounds. One background is $AdS_3 \times S^1 \times T^2$ in which the anti-de Sitter space-time and the circle are at the radius $\sqrt{\alpha'}$. Using path integral techniques, we show…

In this note, we comment on the path integral formulation of string theory on $\mathcal{M}\times\text{S}^3\times\mathbb{T}^4$ where $\mathcal{M}$ is any hyperbolic 3-manifold. In the special case of $k=1$ NS-NS flux, we provide a covariant…

We study worldsheet sphere amplitudes, in the RNS formalism, in superstring theory on $\text{AdS}_3\times X$ with pure NS-NS flux using the near-boundary approximation. By computing a number of amplitudes at low-lying spectral flow, we…

We study string propagation on $AdS_3$ times a compact space from an ``old fashioned'' worldsheet point of view of perturbative string theory. We derive the spacetime CFT and its Virasoro and current algebras, thus establishing the…

String theory on AdS$_3$ with NS-NS fluxes admits a solvable irrelevant deformation which is close to the $T\bar{T}$ deformation of the dual CFT$_2$. This consists of deforming the worldsheet action, namely the action of the…

We calculate the spectrum of a two dimensional CFT on a cylinder, perturbed by a general linear combination of $T\bar{T}$, $J\bar{T}$ and $T\bar{J}$, by utilizing the relation of this problem to certain solvable single trace current-current…

String theory on curved backgrounds has received much attention on account of both its own interest, and of its relation with gauge theories. Despite the progress made in various directions, several quite elementary questions remain…

We analyse the world-sheet perturbations of string theory formulated around $AdS_3$ background. We identify a set of operators that, while added to the world-sheet action, generate the boundary fluctuations of $AdS_3$. The effect of these…

We investigate aspects of holographic duals to time-like warped AdS_3 space-times--which include G\"odel's universe--in string theory. Using worldsheet techniques similar to those that have been applied to AdS_3 backgrounds, we are able to…

I show that the motion of a closed string consisting of $n$ segments in AdS$_3$ can be embedded into the mutation dynamics of the $Y^{n,0}$ brane tiling. The determinant of the Kasteleyn matrix computes the spectral curve. The dynamics is…

We review old and recent results on a special limit of string theory on AdS$_3\times M_7$ with pure NS-NS fluxes: the limit in which the string length $\ell_s=\sqrt{\alpha'}$ equals the AdS$_3$ radius $R $. At this point of the moduli…

In typical examples of the AdS/CFT correspondence, the world-sheet theory with holes in the presence of D-branes is assumed to be equivalent in a low-energy limit to a world-sheet theory without holes for a different background such as…

We propose a worldsheet description for the ${\rm AdS}_5\times {\rm S}^5$ string theory dual to large $N$, free ${\cal N}=4$ super Yang-Mills in four dimensions. The worldsheet theory is a natural generalisation of the recently investigated…