On 1/2 BPS Solutions in M-theory
  We study singular 1/2 BPS solutions in M-theory using 11-dimensional superstar solutions. The superstar solutions and their corresponding plane wave limits could give an insight how one may deform the boundary conditions to get singular, but still physically acceptable, solutions. Starting from M-theory solutions with an isometry, we will also study 10-dimensional solutions coming from these M-theory solutions compactified on a circle. 
Mohsen Alishahiha and Hossein Yavartanoo