Localized Features in Non-Gaussianity from Heavy Physics

Understand

We discuss the possibility that we could obtain some hints of the heavy physics during inflation by analyzing local features of the primordial bispectrum.

• A heavy scalar field could leave large signatures in the primordial spectra through the parametric resonance between its background oscillation and the fluctuations.
• Since the duration of the heavy-mode oscillations is finite, the effect of the resonance is localized in momentum space.
• In this paper, we show that the bispectrum is amplified when such a resonance occurs, and that the peak amplitude of the feature can be O(10^{1-2}), or as large as O(10^5) depending on the type of interactions.