Matrix Model in a Class of Time Dependent Supersymmetric Backgrounds
  We discuss the matrix model in a class of 11D time dependent supersymmetric backgrounds as obtained in hep-th/0508191 . We construct the matrix model action through the matrix regularization of the membrane action in the background. We show that the action is exact to all order of fermionic coordinates. Furthermore We discuss the fuzzy sphere solutions in this background. 
Hong-Zhi Chen, Bin Chen