scholarly journals The Solution to the Cosmological Constant Problem

2019 ◽  
Author(s):  
Brian Craig
Keyword(s):  
Cosmological Constant ◽  
Gamma Rays ◽  
Mass Density ◽  
Empty Space ◽  
Vacuum State ◽  
Cosmological Constant Problem ◽  
New Approach ◽  
Solid Crystal ◽  
Low Mass ◽  
The Universe

To account for the very low mass density associated with Dark Energy and the Cosmological Constant, a new approach to the ground state of empty space is presented. The resulting model for the vacuum state associated with empty space proposes a crystalline-like texture for the chromatic structure of empty space. This vacuum state has the appropriate mass density and predicts acceleration for the Universe expansion. Furthermore, the model predicts that this texture is anisotropic and may lead to measurable changes in the production of electron and positron pairs by gamma rays incident on a solid crystal of low mass density such as graphite.

scholarly journals ON THE COSMOLOGICAL CONSTANT PROBLEM

1996 ◽  
Vol 05 (04) ◽  
pp. 433-440 ◽  
Author(s):  
DHURJATI PRASAD DATTA
Keyword(s):  
Cosmological Constant ◽  
Mechanical Model ◽  
Vacuum Energy ◽  
Quantum Mechanical ◽  
Cosmological Constant Problem ◽  
Molecular Physics ◽  
Simple Quantum ◽  
Time Formalism ◽  
Oppenheimer Approximation ◽  
The Universe

A simple quantum mechanical model of a closed interacting system is studied following the intrinsic time formalism developed recently, on the basis of the modified Born-Oppenheimer approximation. Apart from shedding further insights into the recent results on a possible nongravitating vacuum energy in the universe, the study also offers potentially interesting possibilities even in atomic/molecular physics.

scholarly journals THE POINCARÉ CONJECTURE AND THE COSMOLOGICAL CONSTANT

2011 ◽  
Vol 03 ◽  
pp. 195-202
Author(s):  
M. D. MAIA
Keyword(s):  
Cosmological Constant ◽  
Riemannian Geometry ◽  
Extrinsic Curvature ◽  
Space Time ◽  
Local Change ◽  
Accelerated Expansion ◽  
Observable Effect ◽  
Cosmological Constant Problem ◽  
Expansion Of The Universe ◽  
The Universe

The concept of deformation of Riemannian geometry is reviewed, with applications to gravitation and cosmology. Starting with an analysis of the cosmological constant problem, it is shown that space-times are deformable in the sense of local change of shape. These deformations leave an observable signature in the space-time, characterized by a conserved tensor, associated with a tangent acceleration, defined by the extrinsic curvature of the space-time. In the applications to cosmology, we find that the accelerated expansion of the universe is the observable effect of the deformation, dispensing with the cosmological constant and its problems.

scholarly journals Cosmological constant from the emergent gravity perspective

2014 ◽  
Vol 23 (06) ◽  
pp. 1430011 ◽  
Author(s):  
T. Padmanabhan ◽  
Hamsa Padmanabhan
Keyword(s):  
Cosmological Constant ◽  
Sufficient Conditions ◽  
Integration Constant ◽  
Dimensionless Number ◽  
Late Time ◽  
Field Equations ◽  
Cosmological Constant Problem ◽  
Emergent Gravity ◽  
Background Material ◽  
The Universe

Observations indicate that our universe is characterized by a late-time accelerating phase, possibly driven by a cosmological constant Λ, with the dimensionless parameter [Formula: see text], where LP= (Għ/c3)1/2is the Planck length. In this review, we describe how the emergent gravity paradigm provides a new insight and a possible solution to the cosmological constant problem. After reviewing the necessary background material, we identify the necessary and sufficient conditions for solving the cosmological constant problem. We show that these conditions are naturally satisfied in the emergent gravity paradigm in which (i) the field equations of gravity are invariant under the addition of a constant to the matter Lagrangian and (ii) the cosmological constant appears as an integration constant in the solution. The numerical value of this integration constant can be related to another dimensionless number (called CosMIn) that counts the number of modes inside a Hubble volume that cross the Hubble radius during the radiation and the matter-dominated epochs of the universe. The emergent gravity paradigm suggests that CosMIn has the numerical value 4π, which, in turn, leads to the correct, observed value of the cosmological constant. Further, the emergent gravity paradigm provides an alternative perspective on cosmology and interprets the expansion of the universe itself as a quest towards holographic equipartition. We discuss the implications of this novel and alternate description of cosmology.

THE COSMOLOGICAL CONSTANT PROBLEM

1992 ◽  
Vol 01 (01) ◽  
pp. 145-160 ◽  
Author(s):  
Y. JACK NG
Keyword(s):  
Quantum Mechanics ◽  
Cosmological Constant ◽  
Particle Physics ◽  
Large Scale ◽  
Microscopic Theory ◽  
Large Scale Structure ◽  
Theoretical Expectation ◽  
Cosmological Constant Problem ◽  
Empirical Observation ◽  
The Universe

The cosmological constant is a macroscopic parameter which controls the large-scale structure of the Universe. All observations to date have shown that it is very small. However, our modern microscopic theory of particle physics and gravity suggests that the cosmological constant should be very large. This discrepancy between theoretical expectation and empirical observation constitutes the cosmological constant problem. After a review of the problem, some approaches to its solution are briefly discussed, and then a possible solution is proposed. In this approach, the cosmological constant appears as a constant of integration, unrelated to any parameters in the Lagrangian. The solution makes crucial use of quantum mechanics.

scholarly journals INTRINSICALLY QUANTUM-MECHANICAL GRAVITY AND THE COSMOLOGICAL CONSTANT PROBLEM

2011 ◽  
Vol 26 (32) ◽  
pp. 2375-2389 ◽  
Author(s):  
PHILIP D. MANNHEIM
Keyword(s):  
Cosmological Constant ◽  
Conformal Symmetry ◽  
Zero Point ◽  
Dynamical Symmetry ◽  
Matter Field ◽  
Quantum Mechanical ◽  
Conformal Invariant ◽  
Cosmological Constant Problem ◽  
The Universe ◽  
Matter Fields

We propose that gravity be intrinsically quantum-mechanical, so that in the absence of quantum mechanics the geometry of the universe would be Minkowski. We show that in such a situation gravity does not require any independent quantization of its own, with it being quantized simply by virtue of its being coupled to the quantized matter fields that serve as its source. We show that when the gravitational and matter fields possess an underlying conformal symmetry, the gravitational field and fermionic matter-field zero-point fluctuations cancel each other identically. Then, when the fermions acquire mass by a dynamical symmetry breaking procedure that induces a cosmological constant in such conformal theories, the zero-point fluctuations readjust so as to cancel the induced cosmological constant identically. The zero-point vacuum problem and the cosmological constant vacuum problems thus mutually solve each other. We illustrate our ideas in a completely solvable conformal-invariant model, namely two-dimensional quantum Einstein gravity coupled to a Nambu–Jona-Lasinio self-consistent fermion.

scholarly journals CONSTRAINTS ON EXTRA DIMENSIONS FROM COSMOLOGICAL AND TERRESTRIAL MEASUREMENTS

2001 ◽  
Vol 16 (35) ◽  
pp. 2281-2289 ◽  
Author(s):  
KIMBALL A. MILTON ◽  
RONALD KANTOWSKI ◽  
CHUNG KAO ◽  
YUN WANG
Keyword(s):  
Cosmological Constant ◽  
Extra Dimensions ◽  
Mass Density ◽  
Critical Mass ◽  
Casimir Energy ◽  
Microwave Background ◽  
Background Data ◽  
Cosmic Microwave Background Data ◽  
The Universe ◽  
Recent Laboratory

If quantum fields exist in extra compact dimensions, they will give rise to a quantum vacuum or Casimir energy. That vacuum energy will manifest itself as a cosmological constant. The fact that supernova and cosmic microwave background data indicate that the cosmological constant is of the same order as the critical mass density to close the universe supplies a lower bound on the size of the extra dimensions. Recent laboratory constraints on deviations from Newton's law place an upper limit. The allowed region is so small as to suggest that either extra compact dimensions do not exist, or their properties are about to be tightly constrained by experimental data.

scholarly journals A Theoretical Calculation of the Cosmological Constant Based on a Mechanical Model of Vacuum

2021 ◽  
Author(s):  
Xiao-Song Wang
Keyword(s):  
Cosmological Constant ◽  
Mass Density ◽  
Zero Point ◽  
Momentum Tensor ◽  
Einstein’S Equations ◽  
Field Equations ◽  
Cosmological Constant Problem ◽  
Metric Tensor ◽  
Point Energy ◽  
Einstein's Equations

We suppose that vacuum is filled with a kind of continuously distributed matter, which may be called the $\Omega(1)$ substratum, or the electromagnetic aether. Lord Kelvin believes that the electromagnetic aether must also generate gravity. We also suppose that vacuum is filled with another kind of continuously distributed substance, which may be called the $\Omega(2)$ substratum. Based on a theorem of V. Fock on the mass tensor of a fluid, the contravariant energy-momentum tensors of the $\Omega(1)$ and $\Omega(2)$ substratums are established. Quasi-static solutions of the gravitational field equations in vacuum are obtained. Based on an assumption, relationships between the contravariant energy-momentum tensor of the $\Omega(1)$ and $\Omega(2)$ substratums and the contravariant metric tensor are obtained. Thus, the cosmological constant is calculated theoretically. The $\Omega(1)$ and $\Omega(2)$ substratums may be a possible candidate of the dark energy. The zero-point energy of electromagnetic fields will not appear as a source term in the Einstein's equations. The cosmological constant problem is one of the puzzles in physics. Some people believed that all kinds of energies should appear as source terms in the Einstein's equations. It may be this belief that leads to the cosmological constant problem. The mass density of the $\Omega(1)$ and $\Omega(2)$ substratums is equivalent to that $31.33195$ protons contained in a box with a volume of $1.0 {m}^{3}$.

scholarly journals Energy-Momentum Tensor and Parameters in Cosmological Model

2020 ◽  
Author(s):  
Ying-Qiu Gu
Keyword(s):  
Cosmological Model ◽  
Cosmological Constant ◽  
Energy Momentum Tensor ◽  
Equations Of State ◽  
Mass Density ◽  
Big Bang ◽  
Momentum Tensor ◽  
Ideal Gas ◽  
Dimensional Sphere ◽  
The Universe

In cosmology, the cosmic curvature $K$ and the cosmological constant $\Lambda$ are two most important parameters, whose values have strong influence on the behavior of the universe. By analyzing the energy-momentum tensor and equations of state of ideal gas, scalar, spinor and vector potential in detail, we find that the total mass density of all matter is always positive, and the initial total pressure is negative. Under these conditions, by qualitatively analyzing the global behavior of the dynamical equation of cosmological model, we get the following results: (i) $K= 1$, namely, the global spatial structure of the universe should be a 3-dimensional sphere $S^3$. (ii) $0\le\Lambda < 10 ^ {-24} {\rm ly} ^ {-2}$, the cosmological constant should be zero or an infinitesimal. (iii) $a(t)>0$, the initial singularity of the universe is unreachable, and the evolution of universe should be cyclic in time. This means that the initial Big Bang is impossible at all. Since the matter components considered are quite complete and the proof is very elementary and strict, these logical conclusions should be quite reliable. Obviously, these conclusions will be much helpful to correct some popular misconceptions and bring great convenience to further research other problems in cosmology such as property of dark matter and dark energy.

scholarly journals Wave function of the universe from a matrix-valued first-order formalism

2015 ◽  
Vol 12 (04) ◽  
pp. 1550050
Author(s):  
Sergey I. Kruglov ◽  
Mir Faizal
Keyword(s):  
Wave Function ◽  
Partition Function ◽  
Cosmological Constant ◽  
Eigenvalue Equation ◽  
Cosmological Constant Problem ◽  
First Order ◽  
Superspace Formalism ◽  
Statistical Mechanical ◽  
The Universe ◽  
Spacetime Foam

In this paper, the Wheeler–DeWitt equation in full superspace formalism will be written in a matrix-valued first-order formalism. We will also analyze the Wheeler–DeWitt equation in minisuperspace approximation using this matrix-valued first-order formalism. We will note that this Wheeler–DeWitt equation, in this minisuperspace approximation, can be expressed as an eigenvalue equation. We will use this fact to analyze the spacetime foam in this formalism. This will be done by constructing a statistical mechanical partition function for the Wheeler–DeWitt equation in this matrix-valued first-order formalism. This will lead to a possible solution for the cosmological constant problem.

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