Title:	Confronting phantom inflation with Planck data
Authors:	Iqbal, Asif Malik, Manzoor A Qureshi, Mussadiq H
Keywords:	Inflation CMB Planck
Issue Date:	4-Oct-2018
Publisher:	Springer Netherlands
Citation:	Astrophys Space Sci 2018 363:222
Abstract:	The latest Planck results are in excellent agreement with the theoretical expectations predicted from standard normal inflation based on slow-roll approximation which assumes equation-of-state ω≥−1 . In this work, we study the phantom inflation ( ω<−1 ) as an alternative cosmological model within the slow-climb approximation using two hybrid inflationary fields. We perform Chain Monte Carlo analysis to determine the posterior distribution and best fit values for the cosmological parameters using Planck data and show that current CMB data does not discriminate between normal and phantom inflation. Interestingly, unlike in normal inflation, ω in phantom induced inflation evolves very slowly away from −1 during the inflation. Furthermore, in contrast to the standard normal inflation for which only upper bound on tensor-to-scalar ratio r are possible, we obtain both upper and lower bounds for the two hybrid fields in the phantom scenario. Finally, we discuss prospects of future high precision polarization measurements and show that it may be possible to establish the dominance of one model over the other.
Description:	Open Access
URI:	http://hdl.handle.net/2289/7114
ISSN:	0004-640X 1572-946X (online)
Alternative Location:	https://arxiv.org/abs/1803.07087 https://doi.org/10.1007/s10509-018-3446-3
Copyright:	© Springer Nature B.V. 2018
Appears in Collections:	Research Papers (A&A)

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