Domestic corpuscular inflaton

Giugno, Andrea und Giusti, Andrea G. (2019): Domestic corpuscular inflaton. In: International Journal of Geometric Methods in Modern Physics, Vol. 16, No. 7, 1950108

Abstract

The aim of this paper is to provide a more precise description of the paradigm of corpuscular slow-roll inflation, which was previously introduced by Casadio et al. in [Corpuscular slow-roll inflation, Phys. Rev. D 97 (2018) 024041]. Specifically, we start by expanding the Starobinsky theory on a curved background and then infer the number and nature of the propagating degrees of freedom, both in the true inflationary phase and in a quasi-de Sitter approximation. We correctly find that the particle spectrum contains a transverse trace-free mode and a scalar one. The scalar mode displays a tachyonic nature during the slow-roll phase, due to the instability of the system, whereas it acquires the appropriate oscillatory behavior as the background approaches a critical value of the curvature. These results confirm the fact that the Einstein-Hilbert term acts as a perturbation to the quadratic one, and is responsible for driving the early Universe out of the inflationary phase, thus realizing the inflaton field in terms of pure (corpuscular) gravity.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 0219-8878
• Language: English