The Time-dependent Supersymmetric Configurations in M-theory and Matrix Models

TL;DR

The paper targets time-dependent, half-BPS configurations in M-theory and their DLCQ matrix-model realizations to illuminate nonperturbative dynamics near cosmological singularities. It constructs a broad class of 11D supergravity solutions that preserve at least 16 supersymmetries (Killing spinors with $\Gamma^+\epsilon=0$) and analyzes their isometries to show that supernumerary supersymmetries are generically absent, with extra SUSY arising only in special cases that reduce to homogeneous plane-waves. The authors then define matrix models in these backgrounds using the DLCQ approach, deriving explicit time-dependent bosonic and fermionic actions for backgrounds with exponential warp factors and discussing conceptual limitations due to strong curvature. Together, the work provides a framework linking time-dependent M-theory backgrounds, their plane-wave limits, and nonperturbative matrix-model descriptions with potential cosmological applications and connections to matrix-string theory.

Abstract

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.