Power-law modulation of the scalar power spectrum from a heavy field   with a monomial potential
  The effects of heavy fields modulate the scalar power spectrum during inflation. We analytically calculate the modulations of the scalar power spectrum from a heavy field with a separable monomial potential, i.e. V(\phi)~\phi^n. In general the modulation is characterized by a power-law oscillation which is reduced to the logarithmic oscillation in the case of n=2. 
Qing-Guo Huang and Shi Pi
hep-th astro-ph.CO