Gravitational-Wave Mediated Preheating

Understand

We propose a new preheating mechanism through the coupling of the gravitational field to both the inflaton and matter fields, without direct inflaton-matter couplings.

• The inflaton transfers power to the matter fields through interactions with gravitational waves, which are exponentially enhanced due to an inflation-graviton coupling.
• One such coupling is the product of the inflaton to the Pontryagin density, as in dynamical Chern-Simons gravity.
• The energy scales involved are constrained by requiring that preheating happens fast during matter domination.