Stability analysis for cosmological models in f ( R ) gravity using dynamical system analysis

Shah, Parth (Aff1, Department of Mathematics, BITS Pilani K K Birla Goa Campus, 403726, Sancoale, Goa, India) ; Samanta, Gauranga C. (Aff1, Department of Mathematics, BITS Pilani K K Birla Goa Campus, 403726, Sancoale, Goa, India)

27 May 2019

Abstract: Modified gravity theories have received increased attention lately to understand the late time acceleration of the universe. This viewpoint essentially modifies the geometric components of the universe. Among numerous extension to Einstein’s theory of gravity, theories which include higher order curvature invariant, and specifically the class of f ( R ) theories, have received several acknowledgments. In our current work we try to understand the late time acceleration of the universe by modifying the geometry of the space and using dynamical system analysis. The use of this technique allows to understand the behavior of the universe under several circumstances. Apart from that we study the stability properties of the critical point and acceleration phase of the universe which could then be analyzed with observational data. We consider a particular model f(R)=R-μRc(R/Rc)p \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$f(R) = R - \mu R_{c}(R/R_{c})^{p}$\end{document} with 00 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$0< p < 1, \mu , R_{c} > 0$\end{document} for the study. As a first case we consider the matter and radiation component of the universe with an assumption of no interaction between them. Later, as a second case we take matter, radiation and dark energy (cosmological constant) where study on effects of linear, non-linear and no interaction between matter and dark energy is considered and results have been discussed in detail.

Published in: EPJC 79 (2019) 414 DOI: 10.1140/epjc/s10052-019-6934-x