IIB solutions with N>28 Killing spinors are maximally supersymmetric
arXiv:0710.1829 · doi:10.1088/1126-6708/2007/12/070
Abstract
We show that all IIB supergravity backgrounds which admit more than 28 Killing spinors are maximally supersymmetric. In particular, we find that for all N>28 backgrounds the supercovariant curvature vanishes, and that the quotients of maximally supersymmetric backgrounds either preserve all 32 or N<29 supersymmetries.
27 pages