Abstract
We investigate the consequences of general curved trajectories in multi-field inflation. After setting up a completely general formalism using the mass basis, which naturally accommodates the notion of light and heavy modes, we study in detail the simple case of two successive turns in two-field system. We find the power spectrum of the curvature perturbation receives corrections that exhibit oscillatory features sinusoidal in the logarithm of the comoving wavenumber without slow-roll suppression. We show that this is because of the resonance of the heavy modes inside and outside the mass horizon.
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Gao, X., Gong, JO. Towards general patterns of features in multi-field inflation. J. High Energ. Phys. 2015, 115 (2015). https://doi.org/10.1007/JHEP08(2015)115
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DOI: https://doi.org/10.1007/JHEP08(2015)115