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 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 cosmological constant of emergent spacetime in the Newtonian approximation

2020 ◽  
Vol 29 (13) ◽  
pp. 2050093
Author(s):  
J. C. Castro-Palacio ◽  
P. Fernández de Córdoba ◽  
J. M. Isidro
Keyword(s):  
Cosmological Constant ◽  
Quantum Mechanical ◽  
Nonrelativistic Quantum ◽  
Expectation Value ◽  
Simple Quantum ◽  
Emergent Spacetime ◽  
Nonrelativistic Quantum Mechanics ◽  
The Given ◽  
The Universe ◽  
Matter Fields

We present a simple quantum-mechanical estimate of the cosmological constant of a Newtonian Universe. We first mimic the dynamics of a Newtonian spacetime by means of a nonrelativistic quantum mechanics for the matter contents of the Universe (baryonic and dark) within a fixed (i.e. nondynamical) Euclidean spacetime. Then we identify an operator that plays, on the matter states, a role analogous to that played by the cosmological constant. Finally, we prove that there exists a quantum state for the matter fields, in which the above-mentioned operator has an expectation value equal to the cosmological constant of the given Newtonian Universe.

scholarly journals A Solution of the Cosmological Constant, Using Multiverse Version of Penrose CCC Cosmology, and Enhanced Quantization Compared

2021 ◽  
Author(s):  
Andrew Beckwith
Keyword(s):  
Dark Energy ◽  
Cosmological Constant ◽  
Zero Point ◽  
Small Region ◽  
Negative Energy ◽  
Energy Calculation ◽  
Cosmological Constant Problem ◽  
Point Energy ◽  
Compare And Contrast ◽  
The Universe

We reduplicate the Book “Dark Energy” by M. Li, X-D. Li, and Y. Wang, zero-point energy calculation with an unexpected “length’ added to the ‘width’ of a graviton wavefunction just prior to the entrance of ‘gravitons’ to a small region of space-time prior to a nonsingular start to the universe. We compare this to a solution worked out using Klauder Enhanced quantization, for the same given problem. The solution of the first Cosmological Constant problem relies upon the geometry of the multiverse generalization of CCC cosmology which is explained in this paper. The second solution, used involves Klauder enhanced quantization. We look at energy given by our methods and compare and contrast it with the negative energy of the Rosen model for a mini sub universe and estimate GW frequencies

scholarly journals Is the cosmological constant problem properly posed?

2017 ◽  
Vol 26 (12) ◽  
pp. 1743009 ◽  
Author(s):  
Philip D. Mannheim
Keyword(s):  
Cosmological Constant ◽  
Mechanical Energy ◽  
Zero Point ◽  
Black Body ◽  
Einstein Gravity ◽  
Momentum Tensor ◽  
Matrix Elements ◽  
Microwave Background ◽  
Cosmological Constant Problem ◽  
Quantum Mechanical Energy

In applications of Einstein gravity, one replaces the quantum-mechanical energy–momentum tensor of sources such as the degenerate electrons in a white dwarf or the black-body photons in the microwave background by c-number matrix elements. And not only that, one ignores the zero-point fluctuations in these sources by only retaining the normal-ordered parts of those matrix elements. There is no apparent justification for this procedure, and we show that it is precisely this procedure that leads to the cosmological constant problem. We suggest that solving the problem requires that gravity be treated just as quantum-mechanically as the sources to which it couples, and show that one can then solve the cosmological constant problem if one replaces Einstein gravity by the fully quantum-mechanically consistent conformal gravity theory.

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.

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.

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.

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