  The IP-Glasma initial condition has been highly successful in the
phenomenology of ultra-relativistic heavy ion collisions. The assumption of
boost invariance, however, while good for collision energies probed at the LHC,
limits the use of IP-Glasma to the transverse dynamics of heavy ion collision
to near mid-rapidity. There is a wealth of physics to be explored and
understood in the longitudinal dynamics of heavy ion collisions, and a full
understanding of heavy ion collisions can only come from 3-dimensional studies.
In particular, long range rapidity correlations are seeded in the initial
collision and provide additional information on the high energy nuclear wave
functions that has thus far been inaccessible to the IP-Glasma model. In this
work, we introduce a way to extend the IP-Glasma model to 3+1-dimensions while
preserving its key features.
