Dynamics of purely kinetic $k$-essence in presence of a perfect fluid [CL]

http://arxiv.org/abs/2203.10607


We investigate the dynamics of purely kinetic $k$-essence scalar field in three different scenarios. We begin with the case of a purely kinetic $k$-essence theory and try to formulate a late time accelerating universe model. Then we introduce a perfect fluid in presence of the purely kinetic $k$-essence field and calculate how the features of the previous model are modified. We discuss two cases primarily, in the first case the fluid and the scalar field does not exchange energy and momentum and in the later case the scalar field and the fluid interact non-minimally and exchange energy and momentum. Using dynamical analysis technique, we examine the stability of these systems in the background of a spatially flat Friedman-Lemaitre-Robertson-Walker (FLRW) universe for a particular chosen functional form of $k$-essence kinetic energy term. From the evolution of the effective equation of state parameter of the field-fluid system we conclude that a non-minimally coupled field-fluid scenario can produce physically interesting results. We also find that the $k$-essence field can effectively hide in a radiation background.

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K. Bhattacharya, A. Chatterjee and S. Hussain
Tue, 22 Mar 22
3/82

Comments: 27 pages, 13 figures, Latex file