7 Fundamental Strings , Holography , and Nonlinear Superconformal Algebras

We discuss aspects of holography in the AdS3×S near string geometry of a collection of straight fundamental heterotic strings. We use anomalies and symmetries to determine general features of the dual CFT. The symmetries suggest the appearance of nonlinear superconformal algebras, and we show how these arise in the framework of holographic renormalization methods. The nonlinear algebras imply intricate formulas for the central charge, and we show that in the bulk these correspond to an infinite series of quantum gravity corrections. We also makes some comments on the worldsheet σ-model for strings on AdS3 × S, which is the holographic dual geometry of parallel heterotic strings in five dimensions.