Stability analysis of de Sitter solutions in models with the Gauss-Bonnet term

We study the phase space of an extension of the normal DGP cosmology with a cosmological constant on the brane and curvature effect that is incorporated via the Gauss–Bonnet term in the bulk action. We study late-time cosmological dynamics of this scenario within a dynamical system approach. We show that the stable solution of the cosmological dynamics in this model is a de Sitter phase.

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Effects of Gauss–Bonnet entropy on thermodynamics of Kiselev black hole

International Journal of Modern Physics D ◽

10.1142/s0218271820501011 ◽

2020 ◽

Vol 29 (15) ◽

pp. 2050101

Author(s):

Abdul Jawad ◽

Iqra Siddique ◽

Iarley P. Lobo ◽

Wardat us Salam

Keyword(s):

Black Hole ◽

Extended Phase Space ◽

De Sitter ◽

Extended Phase ◽

First Law Of Thermodynamics ◽

Coexistence Of Phases ◽

Combined Action ◽

The Impact ◽

Bonnet Term ◽

Modified Entropy

In this paper, the thermodynamics of Reissner–Nordström-anti de Sitter black hole surrounded by quintessence is studied and the impact of the Gauss–Bonnet term is measured. The modified entropy, first law of thermodynamics and corresponding Smarr relation are derived due to the combined action of the Gauss–Bonnet term and quintessence fluid. We study the so-called black hole chemistry from the analysis of the corresponding equation-of-state, conjugate potential and the critical points in the extended phase space. To study the phase transitions, we plotted [Formula: see text], [Formula: see text] and [Formula: see text] diagrams and analyzed the conditions for the coexistence of phases.

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Condensation of a scalar field non-minimally coupled to gravity in a cosmological context

Modern Physics Letters A ◽

10.1142/s0217732320502703 ◽

2020 ◽

Vol 35 (32) ◽

pp. 2050270

Author(s):

Amir Ghalee

Keyword(s):

Scalar Field ◽

Energy Density ◽

Condensed Phase ◽

Condensed State ◽

De Sitter ◽

Cosmological Perturbations ◽

Cosmological Context ◽

Background Density ◽

The Universe ◽

Bonnet Term

We present a new mechanism to condense a scalar field coupled to the Gauss–Bonnet term. We propose a scenario in which the condensed state will emerge from the background energy density in the late-Universe. During the radiation and dust-dominated eras, the energy density of the scalar field, [Formula: see text], decreases at a slower rate than the background density. Eventually, [Formula: see text] dominates over the energy density of dust and the scalar field could be condensed. In the condensed phase, we have the de Sitter phase for the universe with [Formula: see text]. Moreover, we study the cosmological perturbations of the model and explore predictions of the model.

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The thermodynamics of a KerrNewmande Sitter black hole

Canadian Journal of Physics ◽

10.1139/p03-110 ◽

2003 ◽

Vol 81 (12) ◽

pp. 1363-1375 ◽

Cited By ~ 23

Author(s):

M H Dehghani ◽

H KhajehAzad

Keyword(s):

Black Hole ◽

Stability Analysis ◽

Hessian Matrix ◽

Shift Factor ◽

De Sitter ◽

Complete Set ◽

Thermodynamic Variables ◽

Renormalization Method ◽

Canonical Ensembles ◽

Grand Canonical

We compute the conserved quantities of the four-dimensional KerrNewmande Sitter (KNdS) black hole through the use of the counterterm renormalization method, and obtain a generalized Smarr formula for the mass as a function of the entropy, the angular momentum, and the electric charge. The first law of thermodynamics associated to the cosmological horizon of KNdS is also investigated. Using the minimal number of intrinsic boundary counterterms, we consider the quasilocal thermodynamics of an asymptotic de SitterReissnerNordstrom black hole, and find that the temperature is equal to the product of the surface gravity (divided by 2π) and the Tolman red-shift factor. We also perform a quasilocal stability analysis by computing the determinant of Hessian matrix of the energy with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles and obtain a complete set of phase diagrams. We then turn to the quasilocal thermodynamics of four-dimensional KerrNewmande Sitter black hole for virtually all possible values of the mass, the rotation, and the charge parameters that leave the quasilocal boundary inside the cosmological event horizon, and perform a quasilocal stability analysis of KNdS black hole.PACS Nos.:04.70.Dy, 04.62.+v, 04.60.m

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Possible fates for the accelerating Universe

Canadian Journal of Physics ◽

10.1139/p06-025 ◽

2006 ◽

Vol 84 (6-7) ◽

pp. 583-589

Author(s):

V Faraoni

Keyword(s):

Stability Analysis ◽

Modified Gravity ◽

Accelerating Universe ◽

Late Time ◽

De Sitter ◽

Recent Proposal ◽

Time Dynamics ◽

Big Rip ◽

Exponential Expansion ◽

General Potential

The accelerating Universe may end in eternal de Sitter expansion, in a Big Rip, or in super-exponential expansion. We discuss a gauge-independent stability analysis of de Sitter space in scalartensor and in modified gravity, the late-time dynamics of a phantom Universe with general potential, and the recent proposal of evading the Big Rip through wormhole tunneling.PACS Nos.: 98.80.k, 04.50.+h, 04.20.q

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COSMOLOGY WITH ADIABATIC MATTER CREATION

International Journal of Modern Physics D ◽

10.1142/s0218271894000563 ◽

1994 ◽

Vol 03 (01) ◽

pp. 327-330 ◽

Cited By ~ 6

Author(s):

WINFRIED ZIMDAHL ◽

DIEGO PAVÓN

Keyword(s):

Stability Analysis ◽

Energy Density ◽

Early Universe ◽

Particle Production ◽

De Sitter ◽

Matter Creation ◽

Production Processes ◽

Density Perturbations ◽

Creation Rate

The standard Friedmann-Lemaître-Robertson-Walker (FLRW) model is modified to include particle production processes. The influence of these processes on the dynamics of the early Universe is investigated. We argue that a sufficiently high creation rate may give rise to an inflationary period. A stability analysis about this background yields growing energy density perturbations during the de Sitter stage.

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Stability analysis of Single-Brane with Gauss-Bonnet Term in a Bulk

Journal of Physics Conference Series ◽

10.1088/1742-6596/1940/1/012025 ◽

2021 ◽

Vol 1940 (1) ◽

pp. 012025

Author(s):

Irsan Rahman ◽

Agussalim Agussalim ◽

Agus Suroso ◽

Freddy P. Zen

Keyword(s):

Stability Analysis ◽

Bonnet Term

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De Sitter Solutions in Einstein–Gauss–Bonnet Gravity

Universe ◽

10.3390/universe7050149 ◽

2021 ◽

Vol 7 (5) ◽

pp. 149

Author(s):

Sergey Vernov ◽

Ekaterina Pozdeeva

Keyword(s):

Effective Potential ◽

Nonlinear Function ◽

Potential Method ◽

Einstein Equations ◽

Late Time ◽

De Sitter ◽

Bonnet Gravity ◽

Energy Models ◽

Acceleration Of The Universe ◽

Bonnet Term

De Sitter solutions play an important role in cosmology because the knowledge of unstable de Sitter solutions can be useful to describe inflation, whereas stable de Sitter solutions are often used in models of late-time acceleration of the Universe. The Einstein–Gauss–Bonnet gravity cosmological models are actively used both as inflationary models and as dark energy models. To modify the Einstein equations one can add a nonlinear function of the Gauss–Bonnet term or a function of the scalar field multiplied on the Gauss–Bonnet term. The effective potential method essentially simplifies the search and stability analysis of de Sitter solutions, because the stable de Sitter solutions correspond to minima of the effective potential.

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Reconstruction procedure for nonlocal Gauss-Bonnet models

International Journal of Modern Physics A ◽

10.1142/s0217751x2040045x ◽

2020 ◽

Vol 35 (02n03) ◽

pp. 2040045

Author(s):

Emilio Elizalde ◽

Ekaterina O. Pozdeeva ◽

Sergey Yu. Vernov

Keyword(s):

Model Parameters ◽

Local Form ◽

De Sitter ◽

Dynamical Equations ◽

Reconstruction Procedure ◽

Bonnet Term

We investigate the cosmological dynamics of nonlocally corrected gravity involving a function of the inverse d’Alembertian acting on the Gauss-Bonnet term. Casting the dynamical equations in local form, we derive the reconstruction procedure. We find conditions on the model parameters that are sufficient for the existence of de Sitter solutions and obtain these solutions explicitly.

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