Related papers: Free field world-sheet correlators for ${\rm AdS}_…
Field theory in space-time with boundary has an interesting sub-sector, where propagator is difference of those with Neumann and Dirichlet boundary conditions. Such boundary-induced theory in the bulk is essentially holomorphic and is…
The type IIB supergravity AdS_3 x S^3 x T^4 background with mixed RR and NSNS 3-form fluxes is a near-horizon limit of a non-threshold bound state of D5-D1 and NS5-NS1 branes. The corresponding superstring world-sheet theory is expected to…
We study bosonic string theory in the light-cone gauge on AdS_3 spacetime with zero radius of curvature (in string units) R/\sqrt{\alpha^\prime}=0. We find that the worldsheet theory admits an infinite number of conserved quantities which…
We discuss the AdS_3/CFT_2 duality of a heterotic three-charge model with (0,4) target space supersymmetry. The worldsheet theory for heterotic strings on the AdS_3 x S^3/Z_N x T^4 near-horizon geometry was constructed by Kutasov, Larsen…
We propose a formula relating scattering S-matrix amplitudes to correlators of a conformal field theory. The proposal implements a flat limit of the field theory, providing an indirect microscopic description of gravitational theories with…
The worldsheet string theory dual to free 4d ${\cal N}=4$ super Yang-Mills theory was recently proposed in arXiv:2104.08263. It is described by a free field sigma model on the twistor space of ${\rm AdS}_5\times {\rm S}^5$, and is a direct…
The scattering equations relate massless scattering kinematics to marked points on a Riemann sphere, and underpin remarkable formulae for the full tree-level S-matrices of many interesting QFTs, including cubic biadjoint scalars, Yang-Mills…
We construct an ambitwistor string that describes Type II supergravity on AdS$_3\times$S$^3$ with pure NS flux. The background Einstein equations ensure that the model is anomaly free. The spectrum consists of supergravity fluctuations…
We use the conjectured strong-weak coupling worldsheet duality between the SL(2)/U(1) and Sine-Liouville conformal field theories to study some properties of degenerate operators and to compute correlation functions in CFT on AdS_3. The…
We comment on certain analogies that have recently emerged between path integral localisation phenomena in minimal tension string theory on $\mathrm{AdS}_3\times S^3\times T^4$ and associated varieties of boundary vertex algebras of 3d…
We discuss the sigma model on the $PSL(n|n)$ supergroup manifold. We demonstrate that this theory is exactly conformal. The chiral algebra of this model is given by some extension of the Virasoro algebra, similar to the $W$ algebra of…
We show the factorization of the three-particle world-sheet S-matrix of AdS_5 x S^5 superstring theory in the near-flat-space limit at one loop order. This is done by computing various scattering amplitudes from Feynman diagrams in the…
One of the few cases of AdS/CFT where both sides of the duality are under good control relates tensionless $k=1$ strings on AdS$_3$ to a two-dimensional symmetric product CFT. Building on prior observations, we propose an exact duality…
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 $. At this point of the moduli…
We discuss string theory on AdS(3)xS(3)xM(4) with particular emphasis on unitarity and state-operator correspondence. The AdS-CFT correspondence, in the Minkowski signature, is re-examined by taking into account the only allowed unitary…
We construct a CFT dual to string theory on AdS$_3$ with pure NS-NS flux. It is given by a symmetric orbifold of a linear dilaton theory deformed by a marginal operator from the twist-2 sector. We compute two- and three-point functions on…
It was recently shown that string theory on $\mathrm{AdS}_3 \times \mathrm{S}^3 \times \mathbb{T}^4$ with minimal NS-NS flux ($k = 1$) is exactly dual to the symmetric orbifold of T4. Here we show that a similar statement also holds for the…
We propose a new $AdS_3/CFT_2$ duality, in which the bulk string theory has a target spacetime $AdS_3$ times a squashed three-sphere $S^3_\flat$, and the dual $CFT_2$ is a symmetric product of sigma models on $R_\phi\times S^3_\flat$,…
In previous work we have shown that large $N$ field theory amplitudes, in Schwinger parametrised form, can be organised into integrals over the stringy moduli space ${\cal M}_{g,n}\times R_{+}^n$. Here we flesh this out into a concrete…
We exploit null vectors of the fractional Virasoro algebra of the symmetric product orbifold to compute correlation functions of twist fields in the large $N$ limit. This yields a new method to derive correlation functions in these orbifold…