Constraints from Astrophysical Data

2020 ◽  
pp. 121-134
Author(s):  
Omar Benhar ◽  
Stefano Fantoni
Keyword(s):  
Astrophysical Data

Ghost dark energy in Rastall theory

2021 ◽  
pp. 2150090
Author(s):  
E. E. Kangal ◽  
M. Salti ◽  
O. Aydogdu
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Text Analysis ◽  
Functional Form ◽  
Expansion Rate ◽  
Dark Energy Density ◽  
Cosmic Expansion ◽  
Astrophysical Data ◽  
Ghost Dark Energy ◽  
History Of

Making use of the generalized form of the Ghost dark energy density, which has the functional form [Formula: see text] where [Formula: see text] represents the Hubble expanding rate, the present accelerated enlargement behavior of the cosmos is investigated from the Rastall theory perspective. After finding a relation for the Hubble cosmic expansion rate, we consider recent cosmology-independent measurements calculated for the expansion history of the cosmos to fit the model via the [Formula: see text]-analysis. Moreover, we discuss the cosmographic properties of the model with the help of some cosmological quantities. We show that our model is stable and consistent with the recent astrophysical data. Also, for our model, we investigate cosmological interpretations of thermodynamics.

Very Large Scale Visualization Methods for Astrophysical Data

2000 ◽  
pp. 115-124 ◽  
Author(s):  
Andrew J. Hanson ◽  
Chi-Wing Fu ◽  
Eric A. Wernert
Keyword(s):  
Large Scale ◽  
Astrophysical Data

Extended gravity at galaxy cluster’s scales

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040057
Author(s):  
Stanislav Alexeyev ◽  
Kirill Kovalkov
Keyword(s):  
Cosmological Constant ◽  
Galaxy Cluster ◽  
The Real ◽  
Astrophysical Data ◽  
Extended Gravity

The new result on Horndeski model asymptotic at Galaxy cluster scales is presented. As the obtained constraint for [Formula: see text] has the same order as for the real cosmological constant we demonstrate that at extra-galactic scales Horndeski model is consistent with existing astrophysical data.

scholarly journals The evidence for a spatially flat Universe

2020 ◽  
Vol 496 (1) ◽  
pp. L91-L95 ◽  
Author(s):  
George Efstathiou ◽  
Steven Gratton
Keyword(s):  
High Precision ◽  
Strong Support ◽  
Inflationary Cosmology ◽  
Density Parameter ◽  
Acoustic Oscillations ◽  
Astrophysical Data ◽  
Flat Universe ◽  
Polarization Spectra ◽  
The Universe ◽  
Good Agreement

ABSTRACT We use a new and statistically powerful Planck likelihood to show that the Planck temperature and polarization spectra are consistent with a spatially flat Universe, in contrast to recent claims in the literature. When combined with other astrophysical data, particularly geometrical measurements of baryon acoustic oscillations, our likelihood constrains the Universe to be spatially flat to extremely high precision. We deduce a curvature density parameter ΩK = 0.0004 ± 0.0018 in good agreement with the 2018 results of the Planck team. In the context of inflationary cosmology, the observations offer strong support for models of inflation with a large number of e-foldings and disfavour models of incomplete inflation.

scholarly journals Black Holes and Wormholes in Extended Gravity

Universe ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 25 ◽  
Author(s):  
Stanislav Alexeyev ◽  
Maxim Sendyuk
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Quantum Theory ◽  
Gravity Models ◽  
Astrophysical Data ◽  
Effective Gravity ◽  
Extended Gravity ◽  
Theory Of Gravity ◽  
Hawking Evaporation

We discuss black hole type solutions and wormhole type ones in the effective gravity models. Such models appear during the attempts to construct the quantum theory of gravity. The mentioned solutions, being, mostly, the perturbative generalisations of well-known ones in general relativity, carry out additional set of parameters and, therefore could help, for example, in the studying of the last stages of Hawking evaporation, in extracting the possibilities for the experimental or observational search and in helping to constrain by astrophysical data.

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