Nuclear Physics B, Volume 931, Pages 216-225 , 01/06/2018

Noether symmetry approach in the cosmological alpha-attractors

Narakorn Kaewkhao, Thanyagamon Kanesom, Phongpichit Channuie

Abstract

In cosmological framework, Noether symmetry technique has revealed a useful tool in order to examine exact solutions. In this work, we first introduce the Jordan-frame Lagrangian and apply the conformal transformation in order to obtain the Lagrangian equivalent to Einstein-frame form. We then analyze the dynamics of the field in the cosmological alpha-attractors using the Noether symmetry approach by focusing on the single field scenario in the Einstein-frame form. We show that with a Noether symmetry the corresponding dynamical system can be completely integrated and the potential exhibited by the symmetry can be exactly obtained. With the proper choice of parameters, the behavior of the scale factor displays an exponential (de Sitter) behavior at the present epoch. Moreover, we discover that the Hubble parameters strongly depends on the initial values of parameters exhibited by the Noether symmetry. Interestingly, it can retardedly evolve and becomes a constant in the present epoch in all cases.

Document Type

Article

Source Type

Journal

ASJC Subject Area

Physics and Astronomy : Nuclear and High Energy Physics


Bibliography


Kaewkhao, N., Kanesom, T., & Channuie, P. (2018). Noether symmetry approach in the cosmological alpha-attractors. Nuclear Physics B, 931216-225. doi:10.1016/j.nuclphysb.2018.04.011

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