https://doi.org/10.1140/epjc/s10052-018-6091-7
Regular Article - Theoretical Physics
Scalar perturbations in cosmological f(R) models: the cosmic screening approach
1
Department of Physics, Istanbul Technical University, 34469, Maslak, Istanbul, Turkey
2
Institute for Astro- and Particle Physics, University of Innsbruck, Technikerstrasse 25/8, A-6020, Innsbruck, Austria
3
Dipartimento di Fisica, Università di Roma ‘Tor Vergata’, via della Ricerca Scientifica 1, 00133, Rome, Italy
4
Institut für Astrophysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
5
Department of Mathematics and Physics, North Carolina Central University, Fayetteville st. 1801, Durham, NC, 27707, USA
6
International Center of Future Science of the Jilin University, 2699 Qianjin St., Changchun City, 130012, China
7
Institute of Radio Astronomy of National Academy of Sciences of Ukraine, 4 Mystetstv str., Kharkiv, 61002, Ukraine
8
Astronomical Observatory, Odessa National University, Dvoryanskaya st. 2, Odessa, 65082, Ukraine
* e-mail: akarsuo@itu.edu.tr
Received:
8
June
2018
Accepted:
19
July
2018
Published online:
30
July
2018
We investigate cosmological perturbations for nonlinear f(R) models within the cosmic screening approach. Matter is considered both in the form of a set of discrete point-like massive bodies and in the form of a continuous pressureless perfect fluid. We perform full relativistic analysis of the first-order theory of scalar perturbations for arbitrary nonlinear f(R) models and demonstrate that scalar potentials 
and 
are determined by a system of only two master equations. Our equations are applicable at all spatial scales as long as the approximation 
(which is usually assumed in studies devoted to cosmological perturbations in f(R) models) works.
© The Author(s), 2018
