Challenges for D-brane large-field inflation with stabilizer fields
  We study possible string theory compactifications which, in the low-energy
limit, describe chaotic inflation with a stabilizer field. We first analyze
type IIA setups where the inflationary potential arises from a D6-brane
wrapping an internal three-cycle, and where the stabilizer field is either an
open-string or bulk K\"ahler modulus. We find that after integrating out the
relevant closed-string moduli consistently, tachyonic directions arise during
inflation which cannot be lifted. This is ultimately due to the shift
symmetries of the type IIA K\"ahler potential at large compactification volume.
This motivates us to search for stabilizer candidates in the complex structure
sector of type IIB orientifolds, since these fields couple to D7-brane Wilson
lines and their shift symmetries are generically broken away from the large
complex structure limit. However, we find that in these setups the challenge is
to obtain the necessary hierarchy between the inflationary and Kaluza-Klein
scales.
