Year: 2008
Type: article
Abstract: We present an explicit cosmological model where inflation and dark energy both could arise from the dynamics of the same scalar field. We present our discussion in the framework where the inflaton field ϕ attains a nearly constant velocity m −1 P |dϕ/d N | ≡ α + βexp(β N ) (where N ≡ ln a is the e-folding time) during inflation. We show that the model with |α| < 0.25 and β < 0 can easily satisfy inflationary constraints, including the spectral index of scalar fluctuations ( n s = 0.96 ± 0.013), tensor-to-scalar ratio ( r < 0.28) and also the bound imposed on Ω ϕ during the nucleosynthesis epoch (Ω ϕ (1 ∼ MeV) < 0.1). In our construction, the scalar field potential always scales proportionally to the square of the Hubble expansion rate. One may thereby account for the two vastly different energy scales associated with the Hubble parameters at early and late epochs. The inflaton energy could also produce an observationally significant effective dark energy at a late epoch without violating local gravity tests.
Source: Classical and Quantum Gravity
Author: Ishwaree P Neupane
Institution: University of Canterbury
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2001076520