Discrete differential forms for cosmological space-times
  In this article we describe applications of the numerical method of discrete differential forms in computational GR. In particular we consider the initial value problem for vacuum space-times that admit plane gravitational waves. As described in an earlier paper the discrete differential form approach can provide accurate results in spherically symmetric space-times. Moreover it is manifestly coordinate independent.   Here we use the polarised Gowdy solution as a testbed for two numerical schemes. One scheme reproduces that solution very well, in particular it is stable for a comparatively long time and converges quadratically. 
Ronny Richter, J\"org Frauendiener