A solution to the initial condition problems of inflation : NATON
  The recent astonishing realization of the negative absolute temperature (NAT)
for motional degrees of freedom \cite{Braun_ea13} inspires its possible
application to the early universe. The existence of the upper bound on the
energy of the system is the sufficient requirement for a NAT and this might
correspond to the Planck scale at the Big Bang model. It has been argued that
standard inflation requires an initial patch that is smooth over distance
scales a bit larger than the causal horizon at the onset of inflation. We show
that this initial condition problem can be solved if the NAT fermion, dubbed
``NATON'', occupies the Universe before the standard inflation is ignited by
providing mini inflation prior to the standard one. As long as NATON dominated
era lasts until at least ten times older than the Planck time, it makes the
Universe homogeneous enough to derive the successful standard inflation.
