Natural Inflation from 5D SUGRA and Low Reheat Temperature
  Motivated by recent cosmological observations of a possibly unsuppressed
primordial tensor component $r$ of inflationary perturbations, we reanalyse in
detail the 5D conformal SUGRA originated natural inflation model of Ref. [1].
The model is a supersymmetric variant of 5D extra natural inflation, also based
on a shift symmetry, and leads to the potential of natural inflation. Coupling
the bulk fields generating the inflaton potential via a gauge coupling to the
inflaton with brane SM states we necessarily obtain a very slow gauge inflaton
decay rate and a very low reheating temperature $T_r\stackrel{<}{_\sim }{\cal
O}(100)$~GeV. Analysis of the required number of e-foldings (from the CMB
observations) leads to values of $n_s$ in the lower range of present Planck
2015 results. Some related theoretical issues of the construction, along with
phenomenological and cosmological implications, are also discussed.
