https://doi.org/10.1140/epjc/s10052-017-5181-2
Letter
Emergence of running dark energy from polynomial f(R) theory in Palatini formalism
1
Astronomical Observatory, Jagiellonian University, Orla 171, 30-244, Kraków, Poland
2
Mark Kac Complex Systems Research Centre, Jagiellonian University, ul. Łojasiewicza 11, 30-348, Kraków, Poland
3
Institute for Theoretical Physics, University of Wrocław, pl. M. Borna 9, 50-204, Wrocław, Poland
* e-mail: marek.szydlowski@uj.edu.pl
Received:
25
July
2017
Accepted:
30
August
2017
Published online:
12
September
2017
We consider FRW cosmology in 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.
© The Author(s), 2017