Related papers: On string backgrounds and (logarithmic) CFT

We briefly review the AdS3/CFT2 correspondence and the holographic issues that arise in the Penrose limit. Exploiting current algebra techniques, developped by D'Appollonio and Kiritsis for the closely related Nappi-Witten model, we obtain…

We describe a large class of exact string backgrounds with a null Killing vector arising, via a limiting \`a la Penrose procedure, from string backgrounds corresponding to coset conformal field theories for compact groups G_N/H_N times a…

Spin Matrix theory (SMT) limits provide a way to capture the dynamics of the AdS/CFT correspondence near BPS bounds. On the string theory side, these limits result in non-relativistic sigma models that can be interpreted as novel…

We study the AdS/CFT correspondence for string states which flow into plane wave states in the Penrose limit. Leading finite radius corrections to the string spectrum are compared with scaling dimensions of finite R-charge BMN-like…

The non-compact CFT of a class of NS-supported pp-wave backgrounds is solved exactly. The associated tree-level covariant string scattering amplitudes are calculated. The S-matrix elements are well-defined, dual but not analytic as a…

I review aspects of string theory on plane wave backgrounds emphasising the connection to gauge theory given by the BMN correspondence. Topics covered include the Penrose limit and its role in deriving the BMN duality from AdS/CFT,…

For any root system corresponding to a semisimple simply-laced Lie algebra a logarithmic CFT is constructed. Characters of irreducible representations were calculated in terms of theta functions.

We prove that all open string theory disc amplitudes in a flat background obey Britto-Cachazo-Feng-Witten (BCFW) on-shell recursion relations, up to a possible reality condition on a kinematic invariant. Arguments that the same holds for…

We review the construction of time-dependent backgrounds with space-like singularities. We mainly consider exact CFT backgrounds. The algebraic and geometric aspects of these backgrounds are discussed. Physical issues, results and…

We show how the Szekeres form of the line element is naturally adapted to study Penrose limits in classical string backgrounds. Relating the "old" colliding wave problem to the Penrose limiting procedure as employed in string theory we…

We study NSR strings in the Nappi-Witten background, which is the Penrose limit of a certain NS5-brane supergravity solution. We solve the theory in the light-cone gauge, obtaining the spectrum, which is space-time supersymmetric. In light…

The interpretation of D-branes in terms of open strings has lead to much interest in boundary conditions of two-dimensional conformal field theories (CFTs). These studies have deepened our understanding of CFT and allowed us to develop new…

We give a complete proof of local background independence of the classical master action for closed strings by constructing explicitly, for any two nearby conformal theories in a CFT theory space, a symplectic diffeomorphism between their…

We set up a strategy for studying large families of logarithmic conformal field theories by using the enlarged symmetries and non--semi-simple associative algebras appearing in their lattice regularizations (as discussed in a companion…

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 construct plane wave backgrounds with time-dependent profiles corresponding to Penrose limits of NS5-branes with transverse space symmetry group broken from SO(4) to SO(2)\times Z_N. We identify the corresponding exact theory as the…

In marked contrast to conventional string theory, ambitwistor strings remain solvable worldsheet theories when coupled to curved background fields. We use this fact to consider the quantization of ambitwistor strings on plane wave metric…

These lecture notes present an elementary introduction to light-cone string field theory, with an emphasis on its application to the study of string interactions in the plane wave limit of AdS/CFT. We summarize recent results and conclude…

We study exact string backgrounds (WZW models) generated by nonsemisimple algebras which are obtained as double extensions of generic D--dimensional semisimple algebras. We prove that a suitable change of coordinates always exists which…

We identify Narain conformal field theories (CFTs) that correspond to code lattices for quantum error-correcting codes (QECC) over integers of cyclotomic fields $Q(\zeta_p)$ $(\zeta_p=e^{\frac{2\pi i}p})$ for general prime $p\geq 3$. This…