122039305
Heterotic string covariant amplitudes and low-energy effective action
Abstract We compute the 3- and 4-point scattering amplitudes for gravitons, antisymmetric tensors, and gauge bosons in the heterotic string model using the covariant path integral formalism. From these amplitudes we deduce all the terms in the low-energy effective action involving cubic and quartic interactions of those fields, that are not affected by pole subtractions. We show that the spin connection should naturally contain torsion whose sign is unambiguously determined by the string amplitudes. The quartic interactions arising from the pure heterotic string part of the amplitudes (i.e. the pieces which are not contained in the SST-scattering amplitudes) are shown to vanish when the gauge field is embedded in the spin connection with torsion ( A μ → ω μ ). Some consequences for compactification are discussed.
118238008
THE LOCAL TERM OF THE ENERGY MOMENTUM TENSOR FOR A QUANTUM SCALAR FIELD IN A CURVED BACKGROUND
117028101
Ten Years of AdS/CFT
10350855
Fusion rules in N=1 superconformal minimal models
Abstract The generalization to N =1 superconformal minimal models of the relation between the modular transformation matrix and the fusion rules in rational conformal field theories, the Verlinde theorem, is shown to provide complete information about the fusion rules, including their fermionic parity. The results for the superconformal Tricritical Ising and Ashkin-Teller models agree with the known rational conformal formulation. The Coulomb gas description of correlation functions in the Ramond sector of N =1 minimal models is also discussed and a previous formulation is completed.
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.
1383405
Free field realization of superstring theory on AdS3
Fil: Hofman, Diego M. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
17065083
Comments on the String dual to N=1 SQCD
We study the String dual to N = 1 SQCD deformed by a quartic superpotential in the quark superfields. We present a unified view of the previous results in the literature and find new exact solutions and new asymptotic solutions. Then we study the Physics encoded in these backgrounds, giving among other things a resolution to an old puzzle related to the beta function and a sufficient criteria for screening. We also extend our results to the SO(Nc) case where we present a candidate for the Wilson loop in the spinorial representation. Various aspects of this line of research are critically analyzed. c.h.badajoz@swansea.ac.uk c.nunez@swansea.ac.uk i.papadimitriou@swansea.ac.uk
7812396
Elaborations on the string dual to N = 1 SQCD
In this paper we make further refinements to the duality proposed between N=1 SQCD and certain string (supergravity plus branes) backgrounds, working in the regime of comparable large number of colors and flavors. Using the string theory solutions, we predict different field theory observables and phenomena like Seiberg duality, gauge coupling and its running, the behavior of Wilson and 't Hooft loops, anomalous dimensions of the quark superfields, quartic superpotential coupling and its running, continuous and discrete anomaly matching. We also give evidence for the smooth interpolation between the Higgs and confining vacua. We provide several matchings between field theory and string theory computations.
119193507
Wilson loops in string duals of walking and flavored systems
We consider the vacuum expectation value of Wilson loop operators by studying the behavior of string probes in solutions of type-IIB string theory generated by N{sub c} D5-branes wrapped on an S{sup 2} internal manifold. In particular, we focus on solutions to the background equations that are dual to field theories with a walking gauge coupling as well as for flavored systems. We present in detail our walking solution and emphasize various general aspects of the procedure to study Wilson loops using string duals. We discuss the special features that the strings show when probing the region associated with the walking of the field-theory coupling.
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.
118385203
Towards multi-scale dynamics on the baryonic branch of Klebanov-Strassler
We construct explicitly a new class of backgrounds in type-IIB supergravity which generalize the baryonic branch of Klebanov-Strassler. We apply a solution-generating technique that, starting from a large class of solutions of the wrapped-D5system, yields the new solutions, and then proceed to study in detail their properties, both in the IR and in the UV. We propose a simple intuitive field theory interpretation of the rotation procedure and of the meaning of our new solutions within the Papadopoulos-Tseytlin ansatz, in particular in relation to the duality cascade in the Klebanov-Strassler solution. The presence in the field theory of different VEVs for operators of dimensions 2, 3 and 6 suggests that this is an important step towards the construction of the string dual of a genuinely multi-scale (strongly coupled) dynamical model.