  String theory axions are interesting candidates for fields whose potential
might be controllable over super-Planckian field ranges and therefore as
possible candidates for inflatons in large field inflation. Axion monodromy
scenarios are setups where the axion shift symmetry is broken by some effect
such that the axion can traverse a large number of periods potentially leading
to super-Planckian excursions. We study such scenarios in type IIA string
theory where the axion shift symmetry is broken by background fluxes. In
particular we calculate the backreaction of the energy density induced by the
axion vacuum expectation value on its own field space metric. We find universal
behaviour for all the compactifications studied where up to a certain critical
axion value there is only a small backreaction effect. Beyond the critical
value the backreaction is strong and implies that the proper field distance as
measured by the backreacted metric increases at best logarithmically with the
axion vev, thereby placing strong limitations on extending the field distance
any further. The critical axion value can be made arbitrarily large by the
choice of fluxes. However the backreaction of these fluxes on the axion field
space metric ensures a precise cancellation such that the proper field distance
up to the critical axion value is flux independent and remains sub-Planckian.
We also study an axion alignment scenario for type IIA compactifications on a
twisted torus with four fundamental axions mixing to leave an axion with an
effective decay constant which is flux dependent. There is a choice of fluxes
for which the alignment parameter is unconstrained by tadpoles and can in
principle lead to a parametrically enhanced effective decay constant. However
we show that these fluxes backreact on the fundamental decay constants so as to
precisely cancel any enhancement.
