2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52349We briefly review the AdS3/CFT2 correspondence and the holographic issues that arise in the Penrose limit. Exploiting current algebra techniques, developped by D'Appollonio and Kiritsis for the closely related Nappi-Witten model, we obtain preliminary results for bosonic string amplitudes in the resulting Hpp-wave background and comment on how to extend them to the superstring.Talk given at the 'Tenth Marcel Grossmann Meeting', 20-26 July 2003, CBPF-ICRA, Rio de Janeiro, Brazil. V2: minor changes and notations changed according to hep-th/0402004High Energy Physics - Theorytext