Oscillatory features in the curvature power spectrum after a sudden turn of the inflationary trajectory

Xian Gao, David Langlois, Shuntaro Mizuno
2013 Journal of Cosmology and Astroparticle Physics  
In the context of two-field inflation characterized by a light direction and a heavy direction, we revisit the question of the impact of the massive modes on the power spectrum produced after a turn in the inflationary trajectory. We consider in particular the resonant effect due to the background oscillations following a sharp turn. Working in the mass basis, i.e. in the basis spanned by the eigenvectors of the effective mass matrix for the perturbations, we provide an analytical estimate of
more » ... e resonant effect, using the in-in formalism. In comparison with earlier estimates, we find the same the spectral dependence but a smaller amplitude. We also compute, again via the in-in formalism, the effect of the direct coupling between the light and heavy modes at the instant of the turn and confirm our previous results obtained via a different method.
doi:10.1088/1475-7516/2013/10/023 fatcat:jor5qil5gje4ndqjjgdehmhbxe