D1/D5 moduli in SCFT and gauge theory, and Hawking radiation

We construct marginal operators of the orbifold SCFT corresponding to all twenty near-horizon moduli in supergravity, including operators involving twist fields which correspond to the blowing up modes. We identify the operators with the supergravity moduli in a 1-1 fashion by inventing a global SO(4) algebra in the SCFT. We analyze the gauge dynamics of the D1/D5 system relevant to the splitting (Q(1), Q(5))-->(Q'(1), Q'(5)) + (Q "(1), Q "(5)) with the help of a linear sigma model. We show in supergravity as well as in SCFT that the absorption cross-section for minimal scalars is the same all over the near-horizon moduli space. (C) 2000 Elsevier Science B.V. All rights reserved.