Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Article number | 028 |
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<mark>Journal publication date</mark> | 18/07/2022 |
<mark>Journal</mark> | Journal of Cosmology and Astroparticle Physics |
Issue number | 7 |
Volume | 2022 |
Publication Status | Published |
<mark>Original language</mark> | English |
Tachyonic preheating is realized when the inflaton repeatedly returns to a convex region of the potential during the post-inflationary oscillating phase. This will induce a strong tachyonic instability and lead to a rapid fragmentation of the coherent field that can complete within a fraction of an e-fold. In this paper, we study the linear regime of this process in a model-independent way. To this purpose, we construct simplified models that provide an analytic Floquet theoretic description of mode growth. This approach captures the essential features of well-motivated tachyonic preheating scenarios, including scenarios in which the inflaton is part of a larger scalar multiplet. We show that tachyonic preheating is efficient if the field excursions are sub-Planckian, can produce gravitational waves in the frequency range of current and future gravitational wave interferometers, and can be consistent with any experimentally allowed tensor-to-scalar ratio.