Penrose limits of non-standard brane intersections

Abstract

The non-standard intersection of two 5-branes and a string can give rise to AdS3 × S3 × S3 × S1. We consider the Penrose limit of this geometry and study the supersymmetry of the resulting pp-wave solution. There is a one-parameter family of Penrose limits associated with the orthogonal rotation of the two foliating circles within the two 3-spheres. Supernumerary Killing spinors arise only when the rotation angle is 45°, for which case we obtain the corresponding light-cone string action that has linearly-realized supersymmetry. We also obtain Penrose limits of other non-standard intersections that give rise to the product of AdS3 or AdS2 and 2-spheres. The resulting pp-waves are supported by multiple constant field strengths.