  While the use of numerical general relativity for modeling astrophysical
phenomena and compact objects is commonplace, the application to cosmological
scenarios is only just beginning. Here, we examine the expansion of a spacetime
using the Baumgarte-Shapiro-Shibata-Nakamura (BSSN) formalism of numerical
relativity in synchronous gauge. This work represents the first numerical
cosmological study that is fully relativistic, non-linear and without symmetry.
The universe that emerges exhibits an average
Friedmann-Lema\"itre-Robertston-Walker (FLRW) behavior, however this universe
also exhibits locally inhomogeneous expansion beyond that expected in linear
perturbation theory around a FLRW background.
