Emergence of dynamical dark energy from polynomial $f(R)$ theory in Palatini formalism

Autor:	Szydlowski, Marek, Stachowski, Aleksander, Borowiec, Andrzej
Rok vydání:	2017
Předmět:	General Relativity and Quantum Cosmology Astrophysics - Cosmology and Nongalactic Astrophysics
Zdroj:	Eur. Phys. J. C77, 603 (2017)
Druh dokumentu:	Working Paper
DOI:	10.1140/epjc/s10052-017-5181-2
Popis:	We consider FRW cosmology in $f(R)= R+ \gamma R^2+\delta R^3$ modified framework. The Palatini approach reduces its dynamics to the simple generalization of Friedmann equation. Thus we study the dynamics in two-dimensional phase space with some details. After reformulation of the model in the Einstein frame, it reduces to the FRW cosmological model with a homogeneous scalar field and vanishing kinetic energy term. This potential determines the running cosmological constant term as a function of the Ricci scalar. As a result we obtain the emergent dark energy parametrization from the covariant theory. We study also singularities of the model and demonstrate that in the Einstein frame some undesirable singularities disappear. Comment: 8 pages, 15 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1707.01948 Zobrazit plný text záznamu View this record from Arxiv