The inflating curvaton
  The primordial curvature perturbation \zeta may be generated by some curvaton
field \sigma, which is negligible during inflation and has more or less
negligible interactions until it decays. In the current scenario, the curvaton
starts to oscillate while its energy density \rho_\sigma is negligible. We
explore the opposite scenario, in which \rho_\sigma drives a few e-folds of
inflation before the oscillation begins. In this scenario for generating \zeta
it is exceptionally easy to solve the \eta problem; one just has to make the
curvaton a string axion, with anomaly-mediated susy breaking which may soon be
tested at the LHC. The observed spectral index n can be obtained with a
potential V\propto \phi^p for the first inflation; p=1 or 2 is allowed by the
current uncertainty in n but the improvement in accuracy promised by Planck may
rule out p=1. The predictions include (i) running n'\simeq 0.0026 (0.0013) for
p=1 (2) that will probably be observed, (ii) non-gaussianity parameter f_NL
\sim -1 that may be observed, (iii) tensor fraction r is probably too small to
ever observed.
