Trajectories with suppressed tensor-to-scalar ratio in Aligned Natural
  Inflation
  In Aligned Natural Inflation, an alignment between different potential terms
produces an inflaton excursion greater than the axion scales in the potential.
We show that, starting from a general potential of two axions with two aligned
potential terms, the effective theory for the resulting light direction is
characterized by four parameters: an effective potential scale, an effective
axion constant, and two extra parameters (related to ratios of the axion scales
and the potential scales in the $2-$field theory). For all choices of these
extra parameters, the model can support inflation along valleys (in the
$2-$field space) that end in minima of the potential. This leads to a
phenomenology similar to that of single field Natural Inflation. For a
significant range of the extra two parameters, the model possesses also higher
altitude inflationary trajectories passing through saddle points of the
$2-$field potential, and disconnected from any minimum. These plateaus end when
the heavier direction becomes unstable, and therefore all of inflation takes
place close to the saddle point, where - due to the higher altitude - the
potential is flatter (smaller $\epsilon$ parameter). As a consequence, a
tensor-to-scalar ratio $r = {\rm O } \left( 10^{-4} - 10^{-2} \right)$ can be
easily achieved in the allowed $n_s$ region, well within the latest $1 \sigma$
CMB contours.
