scholarly journals Phantom dark energy and cosmological solutions without the Big Bang singularity

2010 ◽  
Vol 684 (2-3) ◽  
pp. 69-72 ◽  
Author(s):  
A.N. Baushev
Keyword(s):  
Dark Energy ◽  
Big Bang ◽  
Phantom Dark Energy ◽  
Cosmological Solutions ◽  
The Big Bang ◽  
Big Bang Singularity

An oscillatory big-bang singularity

1986 ◽  
Vol 64 (2) ◽  
pp. 200-203 ◽  
Author(s):  
J. Wainwright
Keyword(s):  
Cosmological Solution ◽  
Big Bang ◽  
Clock Time ◽  
Einstein Field Equations ◽  
Field Equations ◽  
Cosmological Solutions ◽  
Exact Cosmological Solution ◽  
Self Similar ◽  
The Big Bang ◽  
Big Bang Singularity

The big-bang singularities in the exact cosmological solutions of the Einstein field equations that have been studied up to now are power asymptotes in the sense that all scalar polynomials in the curvature tensor diverge monotonically as a power of clock time along the fundamental world lines, as the singularity is approached. One can thus regard the solutions as being asymptotically self-similar near the singularity. In this paper, we illustrate a more complicated type of singularity by giving an example of an exact cosmological solution in which the big-bang singularity is of an oscillatory nature, so that the solution is not asymptotically self-similar.

scholarly journals NEW VISTAS IN BRANEWORLD COSMOLOGY

2002 ◽  
Vol 11 (10) ◽  
pp. 1515-1521 ◽  
Author(s):  
VARUN SAHNI ◽  
YURI SHTANOV
Keyword(s):  
Dark Energy ◽  
Big Bang ◽  
Cosmological Models ◽  
Geometrical Construction ◽  
Braneworld Cosmology ◽  
Higher Dimensional ◽  
Fundamental Forces ◽  
The Big Bang ◽  
Big Bang Singularity

Traditionally, higher-dimensional cosmological models have sought to provide a description of the fundamental forces in terms of a unifying geometrical construction. In this essay we discuss how, in their present incarnation, higher-dimensional "braneworld" models might provide answers to a number of cosmological puzzles including the issue of dark energy and the nature of the big bang singularity.

scholarly journals Deformation of the Wheeler–DeWitt equation

2014 ◽  
Vol 29 (20) ◽  
pp. 1450106 ◽  
Author(s):  
Mir Faizal
Keyword(s):  
Commutation Relation ◽  
Canonical Commutation Relation ◽  
Big Bang ◽  
Minimum Length ◽  
Second Quantization ◽  
Canonical Commutation Relations ◽  
Commutation Relations ◽  
The Big Bang ◽  
Big Bang Singularity ◽  
Modified Theory

In this paper, we will analyze the consequences of deforming the canonical commutation relations consistent with the existence of a minimum length and a maximum momentum. We first generalize the deformation of first quantized canonical commutation relation to second quantized canonical commutation relation. Thus, we arrive at a modified version of second quantization. A modified Wheeler–DeWitt equation will be constructed by using this deformed second quantized canonical commutation relation. Finally, we demonstrate that in this modified theory the big bang singularity gets naturally avoided.

scholarly journals On the stability of Einstein universe in f(R, T, Rμν Tμν) gravity

2018 ◽  
Vol 33 (36) ◽  
pp. 1850216 ◽  
Author(s):  
M. Sharif ◽  
Arfa Waseem
Keyword(s):  
State Parameter ◽  
Big Bang ◽  
Graphical Analysis ◽  
Momentum Tensor ◽  
Field Equations ◽  
Einstein Universe ◽  
Existence And Stability ◽  
The Stability ◽  
The Big Bang ◽  
Big Bang Singularity

This paper investigates the existence and stability of Einstein universe in the context of f(R, T, Q) gravity, where Q = R[Formula: see text] T[Formula: see text]. Considering linear homogeneous perturbations around scale factor and energy density, we formulate static as well as perturbed field equations. We parametrize the stability regions corresponding to conserved as well as non-conserved energy–momentum tensor using linear equation of state parameter for particular models of this gravity. The graphical analysis concludes that for a suitable choice of parameters, stable regions of the Einstein universe are obtained which indicates that the big bang singularity can be avoided successfully by the emergent mechanism in non-minimal matter-curvature coupled gravity.

scholarly journals Quantum Gravity Phenomenology from the Thermodynamics of Spacetime

Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 50
Author(s):  
Ana Alonso-Serrano ◽  
Marek Liška
Keyword(s):  
Quantum Gravity ◽  
Big Bang ◽  
Einstein Equations ◽  
Logarithmic Term ◽  
Quantum Gravity Phenomenology ◽  
Gravity Effects ◽  
Energy Quantum ◽  
The Big Bang ◽  
Big Bang Singularity ◽  
Modified Dynamics

This work is based on the formalism developed in the study of the thermodynamics of spacetime used to derive Einstein equations from the proportionality of entropy within an area. When low-energy quantum gravity effects are considered, an extra logarithmic term in the area is added to the entropy expression. Here, we present the derivation of the quantum modified gravitational dynamics from this modified entropy expression and discuss its main features. Furthermore, we outline the application of the modified dynamics to cosmology, suggesting the replacement of the Big Bang singularity with a regular bounce.

AVOIDING THE BIG BANG SINGULARITY WITH PALATINI f(R) THEORIES

2012 ◽  
Author(s):  
CARLOS BARRAGÁN ◽  
GONZALO J. OLMO ◽  
HÈLIOS SANCHIS-ALEPUZ
Keyword(s):  
Big Bang ◽  
The Big Bang ◽  
Big Bang Singularity

COSMOLOGY WITH DECAYING DARK ENERGY AND COSMOLOGICAL "CONSTANT"

2008 ◽  
Vol 17 (13n14) ◽  
pp. 2527-2533 ◽  
Author(s):  
P. S. WESSON ◽  
B. MASHHOON ◽  
J. M. OVERDUIN
Keyword(s):  
Dark Energy ◽  
Cosmological Constant ◽  
Dimensional Space ◽  
Big Bang ◽  
Higher Dimensional ◽  
The Big Bang ◽  
Good Agreement

We outline an improved cosmology which uses a higher-dimensional space of the type implied by unification, where the cosmological "constant" decays from an unbounded value at the big bang to an acceptable value today. This model leads to a better understanding of inflation and is in good agreement with observations of galaxies.

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