Related papers: Two-dimensional conformal sigma models and exact s…
Target space duality is one of the most profound properties of string theory. However it customarily requires that the background fields satisfy certain invariance conditions in order to perform it consistently; for instance the vector…
We consider non-relativistic conformal quantum mechanical theories that arise by doing discrete light cone quantization of field theories. If the field theory has a gravity dual, then the conformal quantum mechanical theory can have a…
We construct new four-dimensional superstring vacua with extended superconformal symmetries. A non-trivial dilaton background implies the existence of Abelian killing symmetries. These are used to construct dual equivalent backgrounds in a…
The problem of detecting and measuring the repetitiveness of one-dimensional strings has been extensively studied in data compression and text indexing. Our understanding of these issues has been significantly improved by the introduction…
We use an exactly solvable (0,2) supersymmetric conformal field theory with gauge group SO(10) to investigate the superpotential of the corresponding classical string vacuum. We provide evidence that the rational point lies in the…
In the framework of six-dimensional conformal field theories with ${\cal N}=(1,0)$ supersymmetry we develop the map between the holographic description, the field theoretical description and the associated Hanany-Witten set-ups. General…
We present a number of D=4 bosonic and heterotic string solutions with a covariantly constant null Killing vector which, like the solution of Nappi and Witten (NW), correspond to (gauged) WZW models and thus have a direct conformal field…
We review the recently proposed string theory in two dimensional black hole background. Especially, the structure of the duality in the target space is discussed. The duality is analogous to \lq\lq $R \rightarrow 1/R$" symmetry of a…
While it is clear that in some kinematic regime QCD can be described by an effective (as opposed to fundamental) string theory, it is not at all clear how this string theory should be. The `natural' candidate, the bosonic string, leads to…
I illustrate the existence of quasi-realistic heterotic-string models in which all the untwisted Kaehler and complex structure moduli, as well as all of the twisted sectors moduli, are projected out by the generalized GSO projections. I…
(Lecture at the workshop "Basic Problems in String Theory", Yukawa Institute for Theoretical Physics, Kyoto, October 19-21) In this talk, we first review the possibility of matrix models toward a nonperturbative (critical) string theory. We…
In this article we discuss gauge/strings correspondence based on the non-critical strings. With this goal we present several remarkable sigma models with the AdS target spaces. The models have kappa symmetry and are completely integrable.…
We show that $N=8$ {\it self-dual} supergravity theory, which is the consistent background for $N=2$ closed superstring theory in $2+2\-$dimensions, can accommodate the recently discovered two-dimensional dilaton gravity black hole…
Expanding upon earlier results [arXiv:1702.02861], we present a compendium of $\sigma$-models associated with integrable deformations of AdS$_5$ generated by solutions to homogenous classical Yang-Baxter equation. Each example we study from…
Motivated by the study of black attractors in 8D supergravity with 16 supersymmetries, we use the field theory approach and 8D supersymmetry with non trivial central charges to shed light on the exact duality between heterotic string on T^2…
We describe some recent progress in understanding and formulating string theory which is based on extensive studies of strings in lower (D=2) dimension. At the center is a large $W_{\infty}$ symmetry that appears most simply in the matrix…
Several gravitational string backgrounds can be interpreted as 2-dim soliton solutions of reduced axion-dilaton gravity. They include black-hole and worm-hole solutions as well as cosmological models with an exact conformal field theory…
The evolution of a closed NSR string is considered in the background of constant graviton and antisymmetric fields. The $\sigma$-model action is written in a manifestly supersymmetric form in terms of superfields. The first order formalism…
Riemannian coordinates for flat metrics corresponding to three--dimensional conformal Poisson--Lie T--dualizable sigma models are found by solving partial differential equations that follow from the transformations of the connection…
We investigate $2d$ sigma-models with a $2+N$ dimensional Minkowski signature target space metric and Killing symmetry, specifically supersymmetrized, and see under which conditions they might lead to corresponding exact string vacua. It…