scholarly journals The curvaton scenario in brane cosmology: model parameters and their constraints

2010 ◽  
Vol 88 (12) ◽  
pp. 939-945 ◽  
Author(s):  
Hossein Farajollahi ◽  
Arvin Ravanpak
Keyword(s):  
Brane World ◽  
Model Parameters ◽  
Brane Cosmology ◽  
Inflationary Scenario

We have studied the curvaton scenario in brane world cosmology in an intermediate inflationary scenario. This approach has allowed us to find some constraints on different parameters that appear in the model.

scholarly journals Curvaton reheating and intermediate inflation in brane cosmology

2011 ◽  
Vol 89 (10) ◽  
pp. 1015-1021
Author(s):  
Hossein Farajollahi ◽  
Arvin Ravanpak
Keyword(s):  
High Energy ◽  
Brane World ◽  
Model Parameters ◽  
Inflationary Universe ◽  
Brane Cosmology ◽  
Cosmological Constraints ◽  
Energy Regime ◽  
High Energy Regime ◽  
The Universe ◽  
Physical Quantities

In this paper, we study the curvaton reheating mechanism for an intermediate inflationary universe in brane world cosmology. In contrast to our previous work, we assume that when the universe enters the kination era, it is still in the high-energy regime. We then discuss, in detail, the new cosmological constraints on both the model parameters and the physical quantities.

BRANE-WORLD COSMOLOGY

2002 ◽  
Vol 11 (10) ◽  
pp. 1609-1614
Author(s):  
A. A. COLEY
Keyword(s):  
Initial Data ◽  
Cosmological Models ◽  
Brane World ◽  
Initial Singularity ◽  
Brane Cosmology ◽  
Cosmological Scenario ◽  
Self Consistent

It is argued that typically the initial singularity is isotropic in brane world cosmological models. Consequently brane cosmology naturally gives rise to a set of initial data that provide the conditions for inflation to subsequently take place, leading to a self-consistent and viable cosmological scenario.

scholarly journals LIMITS ON THE INTEGRATION CONSTANT OF THE DARK RADIATION TERM IN BRANE COSMOLOGY

2006 ◽  
Vol 21 (17) ◽  
pp. 1377-1382
Author(s):  
A. S. AL-RAWAF
Keyword(s):  
Energy Density ◽  
Photon Energy ◽  
Analytical Methods ◽  
Friedmann Equation ◽  
Brane World ◽  
Integration Constant ◽  
Brane Cosmology ◽  
Dark Radiation ◽  
Brane Model ◽  
Background Photon

We consider the constraints from primordial Helium abundances on the constant of integration of the dark radiation term of the brane-world generalized Friedmann equation derived from the Randall–Sundrum single brane model. We found that — using simple, approximate and semi-analytical methods — the constant of integration is restricted to the range between -9.18 and 5.18 which limits the contribution from dark radiation to be approximately between -28% to 16% of the background photon energy density.

scholarly journals RESTRICTIONS ON DILATONIC BRANE-WORLD MODELS

2002 ◽  
Vol 11 (09) ◽  
pp. 1399-1407 ◽  
Author(s):  
A. ZHUK
Keyword(s):  
Structure Constant ◽  
Brane World ◽  
Fine Structure Constant ◽  
Model Parameters ◽  
Fundamental Constants ◽  
Minimal Coupling ◽  
Liouville Type ◽  
Type Coupling ◽  
Coupling Potential ◽  
Rule Out

We consider dilatonic brane-world models with a non-minimal coupling between dilaton and usual matter on the brane. We demonstrate that the variation of fundamental constants on the brane due to such interaction can lead to strong restrictions on model parameters. In particular, the experimental bounds on the variation of the fine structure constant rule out non-minimal dilatonic models with a Liouville-type coupling potential f(φ) = exp (bφ) where [Formula: see text].

EFFECTIVE COSMOLOGICAL CONSTANT IN BRANE COSMOLOGY

2006 ◽  
Vol 15 (06) ◽  
pp. 895-903
Author(s):  
SEN HU ◽  
JING-RONG WANG
Keyword(s):  
Cosmological Constant ◽  
Vacuum Energy ◽  
Brane World ◽  
Reflection Symmetry ◽  
Brane Cosmology ◽  
Effective Cosmological Constant ◽  
Dimensional Gravity ◽  
Bulk Cosmological Constant ◽  
Dimension One

We consider a brane-world of co-dimension one without reflection symmetry. Through it, we give a possible explanation of the great discrepancy between the vacuum energy and the observed cosmological constant without contradiction to the knowledge we have about our Universe. We also show the gravity observed will be standard four-dimensional gravity as long as the discrepancy of the bulk cosmological constant at different sides of the brane is small enough.

scholarly journals Interacting agegraphic dark energy model in DGP brane-world cosmology: Dynamical system approach

2019 ◽  
Vol 34 (14) ◽  
pp. 1950105 ◽  
Author(s):  
A. Ravanpak ◽  
G. F. Fadakar
Keyword(s):  
Dynamical System ◽  
Dark Energy ◽  
System Approach ◽  
Dark Energy Model ◽  
Acoustic Oscillation ◽  
Energy Model ◽  
Brane World ◽  
Model Parameters ◽  
Dynamical System Approach ◽  
Agegraphic Dark Energy

A proposal to study the effect of interaction in an agegraphic dark energy model in DGP brane-world cosmology is presented in this paper. After explaining the details, we proceed to apply the dynamical system approach to the model to analyze its stability. We first constrain model parameters with a variety of independent observational data such as cosmic microwave background anisotropies, baryon acoustic oscillation peaks and observational Hubble data. Then, we obtain the critical points related to different cosmological epochs. In particular, we conclude that in the presence of interaction, dark energy dominated era could be a stable point if model parameters n and [Formula: see text], obey a given constraint. Also, big rip singularity is avoidable in this model.

Observational constraints of emergent universe in brane-world with Gauss–Bonnet term and dissipative effect

2019 ◽  
Vol 16 (11) ◽  
pp. 1950169 ◽  
Author(s):  
Partha Sarathi Debnath
Keyword(s):  
Equilibrium Points ◽  
Brane World ◽  
Model Parameters ◽  
Type Ii ◽  
Emergent Universe ◽  
World Model ◽  
Imperfect Fluid ◽  
The Stability ◽  
Bonnet Term ◽  
The Eu

Cosmological solutions in the Randall–Sundrum (RS) type II brane-world model including Gauss–Bonnet (GB) term, in the presence of a bulk viscous cosmological fluid are discussed. Transport equations described by Eckart and Israel Stewart are implemented here. Cosmological models admitting emergent universe (EU) of the early universe is explored here in the presence of imperfect fluid described by Eckart theory and Truncated Israel Stewart (TIS) theory and Full Israel Stewart (FIS) theory. We also study the permitted values of the EU model parameters by considering cosmological observational dataset. The stability analysis of the equilibrium points of the dynamical system associated with the evolution in the RS brane including GB term are studied in Eckart theory, TIS theory and FIS theory.

scholarly journals Brane cosmology and the self-tuning of the cosmological constant in the presence of bulk black holes

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
P. Betzios ◽  
O. Papadoulaki
Keyword(s):  
Black Hole ◽  
Cosmological Constant ◽  
Static Solution ◽  
Brane World ◽  
De Sitter ◽  
Brane Cosmology ◽  
Brane Worlds ◽  
Higher Dimensional ◽  
Self Tuning ◽  
Hole Geometry

Abstract Motivated by the holographic self-tuning proposal of the cosmological constant, we generalize and study the cosmology of brane-worlds embedded in a higher-dimensional bulk black hole geometry. We describe the equations and matching conditions in the case of flat, spherical and hyperbolic slicing of the bulk geometry and find the conditions for the existence of a static solution. We solve the equations that govern dynamical geometries in the probe brane limit and we describe in detail the resulting brane-world cosmologies. Of particular interest are the properties of solutions when the brane-world approaches the black hole horizon. In this case the geometry induced on the brane is that of de Sitter, whose entropy and temperature is related to those of the higher dimensional bulk black hole.

scholarly journals BRANE COSMOLOGY WITH NON-STATIC BULK

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 1040-1042 ◽  
Author(s):  
ALI NAYERI
Keyword(s):  
Black Holes ◽  
Thermal Equilibrium ◽  
Brane World ◽  
Late Time ◽  
Time Behavior ◽  
De Sitter ◽  
Brane Cosmology ◽  
Sitter Spacetime ◽  
Inflationary Phase ◽  
Early Universe Cosmology

We study the brane world motion in non-static bulk by generalizing the second Randall-Sundrum scenario Explicitly, we take the bulk to be a Vaidya-AdS metric, which describes the gravitational collapse of a spherically symmetric null dust fluid in Anti-de Sitter spacetime. We point out that during an inflationary phase on the brane, black holes will tend to be thermally nucleated in the bulk We analyze the thermodynamical properties of this brane-world. We point out that during an inflationary phase on the brane, black holes will tend to be thermally nucleated in the bulk. Thermal equilibrium of the system is discussed. We calculate the late time behavior of this system, including 1-loop effects. We argue that at late times a sufficiently large black hole will relax to a point of thermal equilibrium with the brane-world environment. This result has interesting implications for early-universe cosmology.

scholarly journals SINGLE-BRANE WORLD WITH STABILIZED EXTRA DIMENSION

2008 ◽  
Vol 23 (05) ◽  
pp. 761-775 ◽  
Author(s):  
MIKHAIL N. SMOLYAKOV ◽  
IGOR P. VOLOBUEV
Keyword(s):  
Extra Dimension ◽  
Dimensional Space ◽  
Space Time ◽  
Brane World ◽  
Model Parameters ◽  
Dimensional Theory ◽  
Linearized Gravity ◽  
Planck Mass ◽  
Dimensional Space Time ◽  
Scalar Sector

We present a model describing a single brane with tension embedded into a five-dimensional space–time with compact extra dimension, which can be easily stabilized. We examine the linearized gravity in the model and obtain an expression for the four-dimensional Planck mass on the brane in terms of the model parameters. It is also shown that the scalar sector of the effective four-dimensional theory contains a tachyonic mode, and we discuss the problem of stability of the model.

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