The Time-dependent Supersymmetric Configurations in M-theory and Matrix   Models
  In this paper, we study the half-supersymmetric time-dependent configurations in M-theory and their matrix models. We find a large class of 11D supergravity solutions, which keeps sixteen supersymmetries. Furthermore, we investigate the isometries of these configurations and show that in general these configurations have no supernumerary supersymmetries. And also we define the Matrix models in these backgrounds following Discrete Light-Cone Quantization (DLCQ) prescription. 
Bin Chen