scholarly journals Confronting dark energy models mimicking ΛCDM epoch with observational constraints: Future cosmological perturbations decay or future Rip?

2013 ◽  
Vol 718 (4-5) ◽  
pp. 1194-1202 ◽  
Author(s):  
Artyom V. Astashenok ◽  
Sergei D. Odintsov
Keyword(s):  
Dark Energy ◽  
Observational Constraints ◽  
Cosmological Perturbations ◽  
Energy Models

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

Interacting dynamical dark energy with stable high-scale cosmological perturbations at radiation-dominated epoch

2021 ◽  
pp. 2150154
Author(s):  
Roman Neomenko
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Coupling Parameter ◽  
Gravitational Interaction ◽  
State Parameter ◽  
Model Parameters ◽  
Cosmological Perturbations ◽  
Energy Models ◽  
The Impact ◽  
Dynamical Dark Energy

In this paper, the cosmological perturbations of dynamical dark energy and dark matter, which interact non-gravitationally are studied. This dark energy–dark matter non-gravitational interaction is linearly dependent on the energy densities of dark components. However, in the interacting quintessence dark energy models with such type of interaction, the non-adiabatic instabilities of cosmological perturbations at radiation-dominated epoch arise. To avoid this problem, the model of dynamical dark energy was chosen as the basis. Here, the equation of state parameter of dark energy evolves in time but can be assumed constant at early epoch, so this model can be tuned in such a way that the non-adiabatic instabilities would not appear. The drawback of this cosmological model is that the energy densities of dark components can take the negative values for the certain range of interaction parameter, so the conditions for positivity of dark components densities were derived. Using obtained constraints on the model parameters, the impact of coupling parameter on modification of cosmological perturbations’ evolution is analyzed.

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 Cosmological Perturbations in Phantom Dark Energy Models

Universe ◽  
2017 ◽  
Vol 3 (1) ◽  
pp. 22
Author(s):  
Imanol Albarran ◽  
Mariam Bouhmadi-López ◽  
João Morais
Keyword(s):  
Dark Energy ◽  
Cosmological Perturbations ◽  
Energy Models ◽  
Phantom Dark Energy

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.

Sign in / Sign up

Export Citation Format

Share Document