Evolving beyond z=0: insights about the future of stars and the
  intergalactic medium
  We present results from seven cosmological simulations that have been
extended beyond the present era as far as redshift $z=-0.995$ or
$t\approx96\,{\rm Gyr}$, using the Enzo simulation code. We adopt the
calibrated star formation and feedback prescriptions from our previous work on
reproducing the Milky Way with Enzo with modifications to the simulation code,
chemistry and cooling library. We then consider the future behaviour of the
halo mass function (HMF), the equation of state (EOS) of the IGM, and the
cosmic star formation history (SFH). Consistent with previous work, we find a
freeze-out in the HMF at $z\approx-0.6$. The evolution of the EOS of the IGM
presents an interesting case study of the cosmological coincidence problem,
where there is a sharp decline in the IGM temperature immediately after $z=0$.
For the SFH, the simulations produce a peak and a subsequent decline into the
future. However, we do find a turnaround in the SFH after $z\approx-0.98$ in
some simulations, probably due to the limitations of the criteria used for star
formation. By integrating the SFH in time up to $z=-0.92$, the simulation with
the best spatial resolution predicts an asymptotic total stellar mass that is
very close to that obtained from extrapolating the fit of the observed SFR.
Lastly, we investigate the future evolution of the partition of baryons within
a Milky Way-sized galaxy, using both a zoom and a box simulation. Despite
vastly different resolutions, these simulations predict individual haloes
containing an equal fraction of baryons in stars and gas at the time of
freeze-out ($t\approx30\,{\rm Gyr}$).
