scholarly journals Conformal cyclic evolution of phantom energy dominated universe

2020 ◽  
Vol 66 (2 Mar-Apr) ◽  
pp. 209 ◽  
Author(s):  
S. Natarajan ◽  
R. Chandramohan ◽  
R. Swminathan
Keyword(s):  
Dark Matter ◽  
Energy Density ◽  
Quantum Gravity ◽  
Phantom Energy ◽  
Scale Factor ◽  
Scale Factors ◽  
Zero Values ◽  
Work Relationship ◽  
Conformal Cyclic Cosmology ◽  
Canonical Quantum Gravity

From the Wheeler Dewitt solutions, the scale factor of the initial universe is discussed. In this study scale factors from Wheeler Dewitt solutions, loop quantum gravity, and phantom energy dominated stages are compared. Certain modifications have been attempted in scale factor and quantum potentials driven by canonical quantum gravity approaches. Their results are discussed in this work. Despite increment of phantom energy density avoidance of big rip is reported. Scale factors predicted from various models is discussed in this work. Relationship between scale factors and smooth continuation of aeon is discussed by the application of conformal cyclic cosmology. Quantum potentials for various models are correlated and a correction parameter is included on the cosmological constant. Phantom energy dominated, final stage non-singular evolution of the universe is reported. Eternal increment of phantom energy density without interacting with dark matter is reported for the consequence of evolution of the future universe. Also, the non-interacting solutions of phantom energy and dark matter are explained. As the evolution continues even after the final singularity is approached, the validity of conformal cyclic cosmology is predicted. Non zero values for the scale factor for the set of eigenvalues are reported with a graph

scholarly journals Applications of Canonical Quantum Gravity to Cosmology

Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1005
Author(s):  
Claus Gerhardt
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Quantum Gravity ◽  
Canonical Quantum Gravity ◽  
Canonical Quantum

We applied quantum gravitational results to spatially unbounded Friedmann universes and tried to answer some questions related to dark energy, dark matter, inflation, and the missing antimatter.

scholarly journals Reaffirmation of cosmological oscillations in the scale factor from the Pantheon compilation of 1048 Type Ia supernovae

2020 ◽  
Vol 494 (2) ◽  
pp. 2158-2165 ◽  
Author(s):  
H I Ringermacher ◽  
L R Mead
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Energy Density ◽  
Friedmann Equation ◽  
Scale Factor ◽  
Field Energy ◽  
Type Ia Supernovae ◽  
Density Parameter ◽  
Type Ia ◽  
Ia Supernovae

ABSTRACT We observe damped temporal oscillations in the scale factor at a dominant frequency of ∼7 cycles/Hubble-time in the Pantheon compilation of 1048 Type Ia supernovae (SNe Ia). The residual oscillations observed in the Pantheon data closely match and reaffirm our initial observation of oscillations from earlier SNe data (primarily SNLS3 data of Conley 2011) at 2σ confidence. The nearly identical shapes in amplitude, frequency, phase, and damping constant makes it highly likely that the signal is real. Furthermore, two-thirds of the Pantheon SNe cover different portions of the sky compared with SNLS3 strengthening this conclusion. Our model describing the oscillation, presented in an earlier paper, is a simple scalar field harmonic oscillator coupled to the Lambda cold dark matter (ΛCDM) Friedmann equation, but carried into the present epoch. The scalar field energy density plays the role of the dark matter energy density in ΛCDM cosmology, fits well as an average, and closely matches the present dark matter density parameter, suggesting the oscillation plays a role in the dark matter sector. Temporal oscillations in the scale factor and its derivative, as described in this work, would also induce temporal oscillations of the Hubble parameter.

Today’s Standard Models of Particles and Gravity

2018 ◽  
pp. 129-131
Author(s):  
Alvaro De Rújula
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Energy Density ◽  
Quantum Gravity ◽  
Dark Energy Density ◽  
The Standard Model ◽  
Standard Models ◽  
Drawing Board ◽  
Hubble’S Law ◽  
The Universe

The missing particle of the standard model: the “axion.” Our considerable ignorance concerning dark matter and the dark energy density of the Universe. No decent theory of quantum gravity. How all this sends us back to the drawing board, and to return to observations of the Universe, starting with Hubble’s law of its expansion.

scholarly journals CONSTRAINTS IN QUANTUM GEOMETRODYNAMICS

2004 ◽  
Vol 19 (10) ◽  
pp. 1609-1638 ◽  
Author(s):  
ADRIAN P. GENTLE ◽  
NATHAN D. GEORGE ◽  
ARKADY KHEYFETS ◽  
WARNER A. MILLER
Keyword(s):  
Quantum Gravity ◽  
General Setting ◽  
Square Root ◽  
Dynamical Equations ◽  
Dynamic Content ◽  
Quantization Formalism ◽  
Canonical Quantum Gravity ◽  
First Time ◽  
Quantum Geometrodynamics ◽  
Canonical Quantum

We compare different treatments of the constraints in canonical quantum gravity. The standard approach on the superspace of 3-geometries treats the constraints as the sole carriers of the dynamic content of the theory, thus rendering the traditional dynamical equations obsolete. Quantization of the constraints in both the Dirac and ADM square root Hamiltonian approaches leads to the well known problems of time evolution. These problems of time are of both an interpretational and technical nature. In contrast, the geometrodynamic quantization procedure on the superspace of the true dynamical variables separates the issues of quantization from the enforcement of the constraints. The resulting theory takes into account states that are off-shell with respect to the constraints, and thus avoids the problems of time. We develop, for the first time, the geometrodynamic quantization formalism in a general setting and show that it retains all essential features previously illustrated in the context of homogeneous cosmologies.

Legibility Study of Selected Scale Characteristics for Moving-Tape Instruments

1965 ◽  
Vol 7 (6) ◽  
pp. 545-555 ◽  
Author(s):  
Barbara J. Kelso
Keyword(s):  
Air Force ◽  
Reaction Times ◽  
Scale Factor ◽  
Verbal Response ◽  
Scale Factors ◽  
Scale Characteristics ◽  
The Mean ◽  
Standard Deviations ◽  
Vertical Scales ◽  
Speed And Accuracy

A legibility study was performed to investigate the effects of scale factors, graduation marks, orientation of scales, and reading conditions on the speed and accuracy of reading moving-tape instruments. Each of 150 Air Force Officers made 150 self-paced readings from slides of hand drawn tape instruments. Error was expressed as the magnitude of deviation of a subjects' verbal response from the set scale value. An analysis of variance was performed on the mean error scores, standard deviations of error, mean reaction times, and standard deviations of reaction times. The results clearly favored the 1 7/8 inch scale factor over the 1 3/8 inch and the 2 3/8 scale factor. The use of 9 graduation marks was superior to either 0, 1, 3, or 4 graduation marks. Reading conditions had little effect on performance. Horizontal scales were read more rapidly but no more accurately than vertical scales.

scholarly journals Brownian motion and polarized three-dimensional quantum vacuum

2021 ◽  
Vol 67 (4 Jul-Aug) ◽  
Author(s):  
Davide Fiscaletti
Keyword(s):  
Dark Matter ◽  
Brownian Motion ◽  
Energy Density ◽  
Nonlinear Model ◽  
Vacuum Energy ◽  
Three Dimensional ◽  
Vacuum Energy Density ◽  
Quantum Vacuum ◽  
Virtual Particles ◽  
Fundamental Entity

A nonlinear model of Brownian motion is developed in a three-dimensional quantum vacuum defined by a variable quantum vacuum energy density corresponding to processes of creation/annihilation of virtual particles. In this model, the polarization of the quantum vacuum determined by a perturbative fluctuation of the quantum vacuum energy density associated with a fluctuating viscosity, which mimics the action of dark matter, emerges as the fundamental entity which generates the Brownian motion.

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