The time-dependent supersymmetric configurations in M-theory and matrix models

In this Letter, we study the half-supersymmetric time-dependent configurations in M-theory and their matrix models. We find a large class of I I D supergravity solutions, which keeps sixteen supersymmetries. Furthermore, we investigate the isometrics of these configurations and show that in general these configurations have no supernumerary supersymmetry. And also we define the matrix models in these backgrounds following discrete light-cone quantization (DLCQ) prescription. (c) 2005 Elsevier B.V. All rights reserved.