14232422
Four point functions in the SL(2,R) WZW model
Abstract We consider winding conserving four point functions in the SL ( 2 , R ) WZW model for states in arbitrary spectral flow sectors. We compute the leading order contribution to the expansion of the amplitudes in powers of the cross ratio of the four points on the worldsheet, both in the m - and x -basis, with at least one state in the spectral flow image of the highest weight discrete representation. We also perform certain consistency check on the winding conserving three point functions.
117028101
Ten Years of AdS/CFT
119116593
Coulomb integrals and conformal blocks in the AdS3-WZNW model
We study spectral flow preserving four-point correlation functions in the AdS3-WZNW model using the Coulomb gas method on the sphere. We present a multiple integral realization of the conformal blocks and explicitly compute amplitudes involving operators with quantized values of the sum of their spins, i.e., requiring an integer number of screening charges of the first kind. The result is given as a sum over the independent configurations of screening contours yielding a monodromy invariant expansion in powers of the worldsheet moduli. We then examine the factorization limit and show that the leading terms in the sum can be identified, in the semiclassical limit, with products of spectral flow conserving three-point functions. These terms can be rewritten as the m-basis version of the integral expression obtained by J. Teschner from a postulate for the operator product expansion of normalizable states in the H3+-WZNW model. Finally, we determine the equivalence between the factorizations of a particular set of four-point functions into products of two three-point functions either preserving or violating spectral flow number conservation. Based on this analysis we argue that the expression for the amplitude as an integral over the spin of the intermediate operators holds beyond the semiclassical regime, thus corroborating that spectral flow conserving correlators in the AdS3-WZNW model are related by analytic continuation to correlation functions in the H3+-WZNW model.
1383405
Free field realization of superstring theory on AdS3
Fil: Hofman, Diego M. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
122296725
Intrinsic normal-ordered vertex operators from the multiloop N-tachyon amplitude
Abstract We construct vertex operators for arbitrary mass level states of the closed bosonic string. Starting from a generalization of the Koba-Nielsen amplitude which is suitable for an arbitrary genus Riemann surface, we read the vertex operators from the residues of the poles for the intermediate states. Since the original expression is metric independent and normal ordered without the need of inventing any regularization scheme, our vertex operators also possess these properties. We discuss their general features.
125323277
String propagation in non-compact backgrounds
In this lecture we review some recent developments in non-rational conformal field theory, which allow a description of strings moving in non-compact backgrounds. In particular, we discuss recent progress in the SL(2,R) WZW model, which describes string propagation in AdS3.
8824397
Fake supergravity and domain wall stability
We review the generalized Witten-Nester spinor stability argument for flat domain wall solutions of gravitational theories. Neither the field theory nor the solution need be supersymmetric. Nor is the space-time dimension restricted. We develop the non-trivial extension required for AdS-sliced domain walls and apply this to show that the recently proposed "Janus" solution of Type IIB supergravity is stable non-perturbatively for a broad class of deformations. Generalizations of this solution to arbitrary dimension and a simple curious linear dilaton solution of Type IIB supergravity are byproducts of this work.
121982373
Fermionic current algebra in three dimensions
We consider the fermion-boson mapping in three dimensional space-time, in the Abelian case, from the current algebra point of view. It is shown that in a path-integral framework one can derive a general bosonization recipe leading, in the bosonic language, to the correct equal-time current commutators of the original free fermionic theory.
15316691
Supersymmetry and bosonization in three dimensions
Abstract We discuss on the possible existence of a supersymmetric invariance in purely fermionic planar systems and its relation to the fermion-boson mapping in three-dimensional quantum field theory. We consider, as a very simple example, the bosonization of free massive fermions and show that, under certain conditions on the masses, this model displays a supersymmetric-like invariance in the low energy regime. We construct the purely fermionic expression for the supercurrent and the non-linear supersymmetry transformation laws. We argue that the supersymmetry is absent in the limit of massless fermions where the bosonized theory is non-local.
118407162
Heavy-quark potential with dynamical flavors: A first-order transition
We study the static potential between external quark-antiquark pairs in a strongly coupled gauge theory with a large number of colors and massive dynamical flavors, using a dual string description. When the constituent mass of the dynamical quarks is set below a certain critical value, we find a first-order phase transition between a linear and a Coulomb-like regime. Above the critical mass the two phases are smoothly connected. We also study the dependence on the theory parameters of the quark-antiquark separation at which the static configuration decays into specific static-dynamical mesons. © 2008 The American Physical Society.
10105618
Bogomol'nyi bounds and Killing spinors in d = 3 supergravity☆
Abstract We discuss the connection between the construction of Bogomol'nyi bounds and equations in three dimensional gravitational theories and the existence of an underlying N = 2 local supersymmetric structure. We show that, apart from matter self duality equations, a first order equation for the gravitational field (whose consistency condition gives the Einstein equation) can be written as a consequence of the local supersymmetry. Its solvability makes possible the evasion of the no-go scenario for the construction of Killing spinors in asymptotically conical spacetimes. In particular we show that the existence of non-trivial supercovariantly constant spinors is guaranteed whenever field configurations saturate the topological bound.