Related papers: String theory on the Schrodinger pp-wave backgroun…

The tachyon-free nonsupersymmetric string theories in ten dimensions have dilaton tadpoles which forbid a Minkowski vacuum. We determine the maximally symmetric backgrounds for the $USp(32)$ Type I string and the $SO(16)\times SO(16)$…

We compute string amplitudes on pp-waves supported by NS-NS 3-form fluxes and arising in the Penrose limit of AdS3xS3xM. We clarify the role of the non-chiral accidental SU(2) symmetry of the background. We comment on the extension of our…

A brief review is given of the recent solution of a non-compact CFT describing a NS-supported pp-wave background. We will first explain how to compute the three and four-point correlators using current algebra techniques, thereby showing…

We present an exact solution of open bosonic string field theory which can be used to describe any time-independent open string background. The solution generalizes an earlier construction of Kiermaier, Okawa, and Soler, and assumes the…

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…

We study the spectrum around the "antiferromagnetic" states of the planar AdS_5/CFT_4 duality. In contrast to the familiar large-spin limit J \to \infty where each magnon momentum scales as p \sim 1/J << 1, we consider a novel…

We analyse the stringy gravitational wave background based on the current algebra $E^{c}_{2}$. We determine its exact spectrum and construct the modular invariant vacuum energy. The corresponding N=1 extension is also constructed. The…

We find pp wave solutions in string theory with null-like linear dilatons. These provide toy models of big bang cosmologies. We formulate Matrix String Theory in these backgrounds. Near the big bang ``singularity'', the string theory…

We find a decoupling limit of planar N=4 super Yang-Mills (SYM) on R x S^3 in which it becomes equivalent to the ferromagnetic XXX_{1/2} Heisenberg spin chain in an external magnetic field. The decoupling limit generalizes the one found in…

In this paper we consider all consistent extensions of the AdS_5 x S^5 superalgebra, psu(2,2|4), to incorporate brane charges by introducing both bosonic and fermionic (non)central extensions. We study the Inonu-Wigner contraction of the…

Puff Field Theory (PFT) is an example of a non-local field theory which arises from a novel embedding of D-branes in Melvin universe. We study several rotating and pulsating string solutions of the F-string equations of motion in the…

The Penrose method for constructing spherical impulsive gravitational waves is investigated in detail, including alternative spatial sections and an arbitrary cosmological constant. The resulting waves include those that are generated by a…

We generalise the notion of a Killing superalgebra, which arises in the physics literature on supergravity, to general dimension, signature and choice of spinor module and Dirac current. We also allow for Lie algebras as well as…

We study various aspects of N=(4,4) type IIA GS superstring theory in the pp-wave background, which arises as the compactification of maximally supersymmetric eleven-dimensional pp-wave geometry along the spacelike isometry direction. We…

We consider supersymmetric PP-wave limits for different N=1 orbifold geometries of the five sphere S^5 and the five dimensional Einstein manifold T^{1,1}. As there are several interesting ways to take the Penrose limits, the PP-wave…

We analyse the relation between two a priori quite different expansions of the string equations of motion and constraints in a general curved background, namely one based on the covariant Penrose-Fermi expansion of the metric G_{\mu\nu}…

We review the recent progress made towards the classification of supersymmetric solutions in ten and eleven dimensions with emphasis on those of IIB supergravity. In particular, the spinorial geometry method is outlined and adapted to…

We use the S-matrix bootstrap to carve out the space of unitary, crossing symmetric and supersymmetric graviton scattering amplitudes in ten dimensions. We focus on the leading Wilson coefficient $\alpha$ controlling the leading correction…

We construct the pp-wave string associated with the Penrose limit of $Y^{p,q}$ and $L^{p,q,r}$ families of Sasaki-Einstein geometries. We identify in the dual quiver gauge theories the chiral and the non-chiral operators that correspond to…

We derive the necessary and sufficient conditions for the existence of a Killing spinor in N=(1,0) gauge supergravity in six dimensions coupled to a single tensor multiplet, vector multiplets and hypermultiplets. These are shown to imply…