Related papers: AdS2xS2 as an exact heterotic string background

This is the second paper of a series of three. We construct effective open-closed superstring couplings by classically integrating out massive fields from open superstring field theories coupled to an elementary gauge invariant tadpole…

Conical defects of the form $(AdS_3\times S^3)/Z_k$ have an exact orbifold description in worldsheet string theory, which we derive from their known presentation as gauged Wess-Zumino-Witten models. The configuration of strings and…

We develop the perturbation theory of double field theory around arbitrary solutions of its field equations. The exact gauge transformations are written in a manifestly background covariant way and contain at most quadratic terms in the…

We report on some recent results within the string/gauge theory correspondence, both in the conformal and in the non conformal cases, for a recently found class of N=1 dual pairs. These results provide the first cross check of AdS/CFT and…

This thesis primarily dives into investigating the details of four-dimensional vacua within String Theory using the AdS/CFT correspondence. In the first and second part of the thesis, we study the fibred Calabi-Yau and M-theory moduli…

Inspired by the AdS/CFT correspondence, we develop an explicit formal duality between the planar limit of a d-dimensional gauge theory and a classical field theory in a (d+1)-dimensional anti-de Sitter space. The key ingredient is the…

We consider the RNS superstrings in $AdS_3 \times S^3 \times {\cal M}$, where $\cal M$ may be $K3$ or $T^4$, based on $SL(2,R)$ and SU(2) WZW models. We construct the physical states and calculate the spectrum. A subsector of this theory…

It is shown that the heterotic string emerges as a soliton in the type I superstring theory in ten dimensions. The collective coordinates of the soliton are described by a smooth, chiral worldsheet theory. There are eight bosonic and eight…

Circular strings pulsating in $AdS_3 \times S^3 \times T^4$ with mixed R-R and NS-NS three-form fluxes can be described by an integrable deformation of the one-dimensional Neumann-Rosochatius mechanical model. In this article we find a…

A Double Field Theory (DFT) description of gauge symmetry enhancing-breaking in the heterotic string is presented. The construction, based on previous results for the bosonic string, relies on the extension of the tangent frame of DFT. The…

The near boundary limit of string theory in AdS_3 is analysed using the Wakimoto free field representation of SL(2,R). The theory is considered as a direct product of the SL(2,R)/U(1) coset and a free boson. Correlation functions are…

We consider gauge/gravity correspondence between maximally supersymmetric Yang-Mills theory in ($p+1$) dimensions and superstring theory on the near-horizon limit of the D$p$-brane solution. The string-frame metric is AdS$_{p+1}\times…

For string theory on AdS$_3$ with pure NS-NS flux a complete set of DDF operators is constructed, from which one can read off the symmetry algebra of the spacetime CFT. Together with an analysis of the spacetime spectrum, this allows us to…

Chiral gauge theories in two dimensions with (0,2) supersymmetry admit a much broader, and more interesting, class of vacuum solutions than their better studied (2,2) counterparts. In this thesis, we will explore some of the possibilities…

An extended field theory is presented that captures the full SL(2) x O(6,6+n) duality group of four-dimensional half-maximal supergravities. The theory has section constraints whose two inequivalent solutions correspond to minimal D=10…

We study string theory on singular Z_N quotients of AdS_3, corresponding to spaces with conical defects. The spectrum is computed using the orbifold procedure. It is shown that spectral flow may be used to generate the twisted sectors. We…

We propose exact $S$-matrices for the AdS_3/CFT_2 duality between Type IIB strings on AdS_3 x S^3 x M_4 with M_4=S^3 x S^1 or T^4 and the corresponding two-dimensional conformal field theories. We fix the complete two-particle S-matrices…

The heterotic string theory, compactified to four dimensions, has been conjectured to have a duality symmetry (S duality) that transforms the dilaton nonlinearly. If valid, this symmetry could provide an important means of obtaining…

In these lecture notes from the 2002 Cargese summer school we review the progress that has been made towards finding a string theory for QCD (or for pure (super)Yang-Mills theory) following the discovery of the AdS/CFT correspondence. We…

We investigate the stability of the electroweak Z-string at high temperatures. Our results show that while finite temperature corrections can improve the stability of the Z-string, their effect is not strong enough to stabilize the Z-string…