Unbound Particles in Dark Matter Halos
  We investigate unbound dark matter particles in halos by tracing particle
trajectories in a simulation run to the far future (a = 100). We find that the
traditional sum of kinetic and potential energies is a very poor predictor of
which dark matter particles will eventually become unbound from halos. We also
study the mass fraction of unbound particles, which increases strongly towards
the edges of halos, and decreases significantly at higher redshifts. We discuss
implications for dark matter detection experiments, precision calibrations of
the halo mass function, the use of baryon fractions to constrain dark energy,
and searches for intergalactic supernovae.
