@Article{AkarsuKaKuNuÖzSh:2020:ThFeOb,
author = "Akarsu, {\"O}zg{\"u}r and Katirci, Nihan and Kumar, Suresh and
Nunes, Rafael da Costa and {\"O}zt{\"u}rk, Burcu and Sharma,
Shivani",
affiliation = "{Istanbul Technical University} and {Istanbul Technical
University} and {BITS Pilani} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Istanbul Technical University} and {BITS
Pilani}",
title = "Rastall gravity extension of the standard \Λ CDM model:
theoretical features and observational constraints",
journal = "European Physical Journal C",
year = "2020",
volume = "80",
number = "11",
pages = "e1050",
month = "Nov.",
abstract = "We present a detailed investigation of the Rastall gravity
extension of the standard CDM model. We review the model for two
simultaneous modifications of different nature in the Friedmann
equation due to the Rastall gravity: the new contributions of the
material (actual) sources (considered as effective source) and the
altered evolution of the material sources. We discuss the
role/behavior of these modifications with regard to some low
redshift tensions, including the so-called H0 tension, prevailing
within the standard CDM. We constrain the model at the level of
linear perturbations, and obtain the first constraints through a
robust and accurate analysis using the latest full Planck cosmic
microwave background (CMB) data, with and without including baryon
acoustic oscillations (BAO) data. We find that the Rastall
parameter (null for general relativity) is consistent with zero at
68% CL (with a tendency towards positive values, \−0.0001
<< 0.0007 (CMB+BAO) at 68% CL), which in turn implies no
significant statistical evidence for deviation from general
relativity, and also a precision of O(10\−4) for the
coefficient \−1/2 of the term g\μ\ν R in the
Einstein field equations of general relativity (guaranteeing the
local energy-momentum conservation). We explore the consequences
led by the Rastall gravity on the cosmological parameters in the
light of the observational analyses. It turns out that the
effective source, with a present-day density parameter X0 =
\−0.0010±0.0013 (CMB+BAO, 68% CL), dynamically screens the
usual vacuum energy at high redshifts, but this mechanism barely
works due to the oppoa e-mail: akarsuo@itu.edu.tr b e-mail:
nihan.katirci@itu.edu.tr c e-mail:
suresh.kumar@pilani.bits-pilani.ac.in (corresponding author) d
e-mail: rafadcnunes@gmail.com e e-mail: ozturkburc@itu.edu.tr f
e-mail: p20170025@pilani.bits-pilani.ac.in sition by the altered
evolution of cold dark matter. Consequently, two simultaneous
modifications of different nature in the Friedmann equation by the
Rastall gravity act against each other, and do not help to
considerably relax the low redshift tensions, including the
so-called H0 tension. Our results may offer a guide for the
research community that studies the Rastall gravity in various
aspects of gravitation and cosmology.",
doi = "10.1140/epjc/s10052-020-08586-4",
url = "http://dx.doi.org/10.1140/epjc/s10052-020-08586-4",
issn = "1434-6044",
language = "en",
targetfile = "Akarsu_rastall.pdf",
urlaccessdate = "07 maio 2024"
}