Dynamics of polynomial Chaplygin gas warm inflation

By assuming the specific Chaplygin gas model, we study the reconstruction of warm inflation model with the help of tensor-to-scalar ratio [Formula: see text] and scalar spectral index [Formula: see text]. In this regard, we take flat Friedmann–Robertson–Walker (FRW) metric and discuss the general forms of dissipative coefficient [Formula: see text] as well as effective potential [Formula: see text] for two dissipative regimes i.e., the weak and strong. We use inflationary parameters such as slow-roll parameters, power spectrum of the curvature perturbation, tensor spectrum, spectral index, scalar-to-tensor ratio and Hubble parameter to find the generalized form of dissipative coefficient and effective potential. We discuss the results of dissipative coefficient and reconstructed potential in detail for the specific choice of tensor-to-scalar ratio [Formula: see text] and scalar spectral index [Formula: see text].

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Weak and strong warm logamediate anisotropic inflationary universe model

Canadian Journal of Physics ◽

10.1139/cjp-2019-0623 ◽

2020 ◽

Vol 98 (11) ◽

pp. 1029-1038

Author(s):

Wajiha Javed ◽

Iqra Nawazish ◽

Mohsin Raza Khan ◽

Ali Övgün

Keyword(s):

Bianchi Type ◽

Scalar Potential ◽

Cosmological Parameters ◽

Chaplygin Gas ◽

Inflationary Universe ◽

Type I ◽

Field Equations ◽

Warm Inflation ◽

Slow Roll ◽

Rotationally Symmetric

In this paper we investigate a warm inflation scenario of a locally rotationally symmetric Bianchi type-I model using a background of modified Chaplygin gas. We determine the field equations and perturbations parameters, such as the scalar power spectrum, scalar spectral index, scalar potential, and tensor-to-scalar ratio under the slow roll approximation. We determine these parameters in the direction of the Hubble parameter during both the weak and strong logamediate inflationary regimes. These cosmological parameters show that the anisotropic model is compatible with WMAP 7 from the 2018 Planck observational data.

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Chaplygin gas inspired non-canonical scalar field warm inflation

Astroparticle Physics ◽

10.1016/j.astropartphys.2019.102402 ◽

2020 ◽

Vol 117 ◽

pp. 102402 ◽

Cited By ~ 1

Author(s):

Abdul Jawad ◽

Azmat Rustam

Keyword(s):

Scalar Field ◽

Chaplygin Gas ◽

Warm Inflation ◽

Canonical Scalar Field

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Weak and Strong Warm Logamediate Anisotropic Inflationary Universe Model

10.20944/preprints201906.0252.v1 ◽

2019 ◽

Author(s):

Wajiha Javed ◽

Iqra Nawazish ◽

Mohsin Raza Khan ◽

Ali Övgün

Keyword(s):

Bianchi Identity ◽

Scalar Potential ◽

Chaplygin Gas ◽

Inflationary Universe ◽

Type I ◽

Field Equations ◽

Warm Inflation ◽

Slow Roll ◽

Scalar Spectral Index ◽

Rotationally Symmetric

This paper is given to the investigation of warm inflation using Modified Chaplygin gas in the background of locally rotationally symmetric Bianchi Identity type I. We find out the field equations and perturbations parameters such as; scalar power spectrum, scalar spectral index, scalar potential and tensor to scalar ratio under slow roll approximation. We find out these parameters in directional of Hubble parameter during the Logamediate inflationary regime in weak and strong case. These comological parameters shows that the anisotropic model is also compatible WMAP$7$ with recent observational data Planck $2018$.

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Dynamical system analysis of FLRW models with Modified Chaplygin gas

Scientific Reports ◽

10.1038/s41598-020-80396-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ali Osman Yılmaz ◽

Ertan Güdekli

Keyword(s):

Dynamical System ◽

Equation Of State ◽

Energy Density ◽

System Analysis ◽

Chaplygin Gas ◽

Modified Chaplygin Gas ◽

State Spaces ◽

The Universe ◽

Matter Energy ◽

Far Future

AbstractWe investigate Friedmann–Lamaitre–Robertson–Walker (FLRW) models with modified Chaplygin gas and cosmological constant, using dynamical system methods. We assume $$p=(\gamma -1)\mu -\dfrac{A}{\mu ^\alpha }$$ p = ( γ - 1 ) μ - A μ α as equation of state where $$\mu$$ μ is the matter-energy density, p is the pressure, $$\alpha$$ α is a parameter which can take on values $$0<\alpha \le 1$$ 0 < α ≤ 1 as well as A and $$\gamma$$ γ are positive constants. We draw the state spaces and analyze the nature of the singularity at the beginning, as well as the fate of the universe in the far future. In particular, we address the question whether there is a solution which is stable for all the cases.

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Late Time Attractors of Some Varying Chaplygin Gas Cosmological Models

Symmetry ◽

10.3390/sym13050769 ◽

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.

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