Perturbative instability of inflationary cosmology from quantum potentials

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Date

2017

Journal Title

Journal ISSN

Volume Title

Type

Article

Publisher

INDIAN ASSOC CULTIVATION SCIENCE

Series Info

INDIAN JOURNAL OF PHYSICS;Volume: 91 Issue: 9 Pages: 1135-1143

Doi

Scientific Journal Rankings

Abstract

It was argued that the Raychaudhuri equation with a quantum correction term seems to avoid the Big Bang singularity and to characterize an everlasting Universe (Ali and Das in Phys Lett B 741:276, 2015). Critical comments on both conclusions and on the correctness of the key expressions of this work were discussed in literature (Lashin in Mod Phys Lett 31:1650044, 2016). In the present work, we have analyzed the perturbative (in) stability conditions in the inflationary era of the early Universe. We conclude that both unstable and stable modes are incompatible with the corresponding ones obtained in the standard FLRW Universe. We have shown that unstable modes do exist at small (an) isotropic perturbation and for different equations of state. Inequalities for both unstable and stable solutions with the standard FLRW space were derived. They reveal that in the FLRW flat Universe both perturbative instability and stability are likely. While negative stability modes have been obtained for radiation- and matter-dominated eras, merely, instability modes exist in case of a finite cosmological constant and also if the vacuum energy dominates the cosmic background geometry.

Description

Accession Number: WOS:000411375700016

Keywords

University for October Quantum cosmology, Perturbation theory, Inflationary universe

Citation

Cited References in Web of Science Core Collection: 52