Fine Features in the Primordial Power Spectrum
Kumazaki, Kohei (Nagoya University)

A possible origin of the anomalous dip and bump in the primordial power \\\\r\\\\nspectrum, which are reconstructed from WMAP data corresponding to \\\\r\\\\nthe multipole $\\\\\\\\ell=100\\\\\\\\sim 140$ by using the inversion method, \\\\r\\\\nis investigated as a consequence of \\\\r\\\\nmodification of scalar field dynamics in the inflation era. \\\\r\\\\nUtilizing\\\\r\\\\nan analytic formula to handle higher order corrections to the slow-roll\\\\r\\\\napproximation, we evaluate the relation between a detailed shape of\\\\r\\\\ninflaton potential and a fine structure in the primordial power\\\\r\\\\nspectrum. We conclude that it is unlikely to generate the observed\\\\r\\\\ndip and bump in the power spectrum by adding any features in the\\\\r\\\\ninflaton potential. Though we can make a fine enough shape in the\\\\r\\\\npower spectrum by controlling the feature of the potential, the\\\\r\\\\namplitude of the dip and bump becomes too small in that case.