scholarly journals Updated observational constraints on quintessence dark energy models

2018 ◽  
Vol 97 (4) ◽  
Author(s):  
Jean-Baptiste Durrive ◽  
Junpei Ooba ◽  
Kiyotomo Ichiki ◽  
Naoshi Sugiyama
Keyword(s):  
Dark Energy ◽  
Observational Constraints ◽  
Energy Models

scholarly journals The growth factor parametrization versus numerical solutions in flat and non-flat dark energy models

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
A. M. Velasquez-Toribio ◽  
Júlio C. Fabris
Keyword(s):  
Dark Energy ◽  
Growth Factor ◽  
Free Parameter ◽  
Numerical Solutions ◽  
Accelerated Expansion ◽  
Observational Constraints ◽  
Good Correspondence ◽  
Energy Models ◽  
Precision Level ◽  
Curvature Parameter

AbstractIn the present investigation we use observational data of $$ f \sigma _ {8} $$ f σ 8 to determine observational constraints in the plane $$(\Omega _{m0},\sigma _{8})$$ ( Ω m 0 , σ 8 ) using two different methods: the growth factor parametrization and the numerical solutions method for density contrast, $$\delta _{m}$$ δ m . We verified the correspondence between both methods for three models of accelerated expansion: the $$\Lambda CDM$$ Λ C D M model, the $$ w_{0}w_{a} CDM$$ w 0 w a C D M model and the running cosmological constant RCC model. In all case we consider also the curvature as free parameter. The study of this correspondence is important because the growth factor parametrization method is frequently used to discriminate between competitive models. Our results we allow us to determine that there is a good correspondence between the observational constrains using both methods. We also test the power of the $$ f\sigma _ {8} $$ f σ 8 data to constraints the curvature parameter within the $$ \Lambda CDM $$ Λ C D M model. For this we use a non-parametric reconstruction using Gaussian processes. Our results show that the $$ f\sigma _ {8}$$ f σ 8 data with the current precision level does not allow to distinguish between a flat and non-flat universe.

scholarly journals Taxonomy of Dark Energy Models

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 163
Author(s):  
Verónica Motta ◽  
Miguel A. García-Aspeitia ◽  
Alberto Hernández-Almada ◽  
Juan Magaña ◽  
Tomás Verdugo
Keyword(s):  
Dark Energy ◽  
Cold Dark Matter ◽  
Accelerated Expansion ◽  
Energy Component ◽  
The Past ◽  
Energy Models ◽  
The Status ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Unknown Component

The accelerated expansion of the Universe is one of the main discoveries of the past decades, indicating the presence of an unknown component: the dark energy. Evidence of its presence is being gathered by a succession of observational experiments with increasing precision in its measurements. However, the most accepted model for explaining the dynamic of our Universe, the so-called Lambda cold dark matter, faces several problems related to the nature of such energy component. This has led to a growing exploration of alternative models attempting to solve those drawbacks. In this review, we briefly summarize the characteristics of a (non-exhaustive) list of dark energy models as well as some of the most used cosmological samples. Next, we discuss how to constrain each model’s parameters using observational data. Finally, we summarize the status of dark energy modeling.

scholarly journals DARK ENERGY, WITH SIGNATURES

2010 ◽  
Vol 19 (14) ◽  
pp. 2325-2330
Author(s):  
SOURISH DUTTA ◽  
ROBERT J. SCHERRER ◽  
STEPHEN D. H. HSU
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Energy Scale ◽  
Fine Tuning ◽  
Time Dependent ◽  
Late Time ◽  
Particle Content ◽  
Energy Field ◽  
Energy Models ◽  
New Energy

We propose a class of simple dark energy models which predict a late-time dark radiation component and a distinctive time-dependent equation of state w(z) for redshift z < 3. The dark energy field can be coupled strongly enough to standard model particles to be detected in colliders, and the model requires only modest additional particle content and little or no fine-tuning other than a new energy scale of order milli-electron volts.

scholarly journals Late Time Attractors of Some Varying Chaplygin Gas Cosmological Models

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 769
Author(s):  
Martiros Khurshudyan ◽  
Ratbay Myrzakulov
Keyword(s):  
Dark Energy ◽  
Gravitational Interaction ◽  
Chaplygin Gas ◽  
Cosmological Models ◽  
Late Time ◽  
Time Behavior ◽  
Coincidence Problem ◽  
Energy Models ◽  
Non Linear ◽  
Bayesian Machine Learning

The goal of this paper is to study new cosmological models where the dark energy is a varying Chaplygin gas. This specific dark energy model with non-linear EoS had been often discussed in modern cosmology. Contrary to previous studies, we consider new forms of non-linear non-gravitational interaction between dark matter and assumed dark energy models. We applied the phase space analysis allowing understanding the late time behavior of the models. It allows demonstrating that considered non-gravitational interactions can solve the cosmological coincidence problem. On the other hand, we applied Bayesian Machine Learning technique to learn the constraints on the free parameters. In this way, we gained a better understanding of the models providing a hint which of them can be ruled out. Moreover, the learning based on the simulated expansion rate data shows that the models cannot solve the H0 tension problem.

scholarly journals Testing H0 in acoustic dark energy models with Planck and ACT polarization data

2020 ◽  
Vol 102 (12) ◽  
Author(s):  
Meng-Xiang Lin ◽  
Wayne Hu ◽  
Marco Raveri
Keyword(s):  
Dark Energy ◽  
Polarization Data ◽  
Energy Models
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