scholarly journals Quantum cosmology with varying speed of light and Bohmian trajectories

2007 ◽  
Vol 39 (6) ◽  
pp. 795-813 ◽  
Author(s):  
F. Shojai ◽  
S. Molladavoudi
Keyword(s):  
Quantum Cosmology ◽  
Speed Of Light ◽  
Bohmian Trajectories

QUANTUM COSMOLOGY IN ANISOTROPIC COSMOLOGICAL MODELS WITH SCALAR–TENSOR THEORIES

2001 ◽  
Vol 10 (06) ◽  
pp. 943-956
Author(s):  
SUBENOY CHAKRABORTY
Keyword(s):  
Wave Function ◽  
Quantum Cosmology ◽  
Classical Limit ◽  
Cosmological Models ◽  
Integral Formulation ◽  
Causal Interpretation ◽  
Anisotropic Cosmological Models ◽  
Bohmian Trajectories ◽  
The Universe ◽  
Method Of Steepest Descent

This paper deals with quantum cosmological phenomena in anisotropic cosmological models with nonminimally coupled scalor field. With proper transformation of the field variables, the Wheeler–Dewitt (WD) equation looks simple in form and solutions are obtained using separable form of the wave function. Using part integral formulation, the wave function of the Universe has been evaluated by the method of steepest descent. Finally, the causal interpretation has been done using quantum Bohmian trajectories and also we study the classical limit of some particular solutions of these quantum models.

scholarly journals CAUSAL LOOP QUANTUM COSMOLOGY IN MOMENTUM SPACE

2009 ◽  
Vol 18 (01) ◽  
pp. 83-93
Author(s):  
ALI SHOJAI ◽  
FATIMAH SHOJAI
Keyword(s):  
Cosmological Constant ◽  
Momentum Space ◽  
Quantum Cosmology ◽  
Cosmological Solution ◽  
Dynamical Variable ◽  
Loop Quantum Cosmology ◽  
Causal Interpretation ◽  
Causal Loop ◽  
Bohmian Trajectories

We shall show that it is possible to make a causal interpretation of loop quantum cosmology using the momentum as the dynamical variable. We shall show that one can derive Bohmian trajectories. For a sample cosmological solution with cosmological constant, the trajectory is plotted.

scholarly journals Silent initial conditions for cosmological perturbations with a change of spacetime signature

2018 ◽  
Vol 27 (05) ◽  
pp. 1850050 ◽  
Author(s):  
Jakub Mielczarek ◽  
Linda Linsefors ◽  
Aurelien Barrau
Keyword(s):  
Quantum Cosmology ◽  
Transition Point ◽  
Initial Conditions ◽  
Vacuum State ◽  
Cosmological Perturbations ◽  
Speed Of Light ◽  
Scale Invariant ◽  
Poincaré Algebra ◽  
The One ◽  
Initial Power

Recent calculations in loop quantum cosmology suggest that a transition from a Lorentzian to a Euclidean spacetime might take place in the very early universe. The transition point leads to a state of silence, characterized by a vanishing speed of light. This behavior can be interpreted as a decoupling of different space points, similar to the one characterizing the BKL phase. In this study, we address the issue of imposing initial conditions for the cosmological perturbations at the transition point between the Lorentzian and Euclidean phases. Motivated by the decoupling of space points, initial conditions characterized by a lack of correlations are investigated. We show that the “white noise” gains some support from analysis of the vacuum state in the deep Euclidean regime. Furthermore, the possibility of imposing the silent initial conditions at the trans-Planckian surface, characterized by a vanishing speed for the propagation of modes with wavelengths of the order of the Planck length, is studied. Such initial conditions might result from the loop deformations of the Poincaré algebra. The conversion of the silent initial power spectrum to a scale-invariant one is also examined.

scholarly journals Quantum cosmology with varying speed of light: Canonical approach

2008 ◽  
Vol 660 (1-2) ◽  
pp. 1-6 ◽  
Author(s):  
P. Pedram ◽  
S. Jalalzadeh
Keyword(s):  
Quantum Cosmology ◽  
Speed Of Light ◽  
Canonical Approach

The Uncertainty Principle Derived by The Finite Transmission Speed of Light and Information

2014 ◽  
Vol 3 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Piero Chiarelli
Keyword(s):  
Uncertainty Principle ◽  
Large Scale ◽  
Uncertainty Relations ◽  
Speed Of Light ◽  
Energy Fluctuation ◽  
Hydrodynamic Analogy ◽  
Non Local ◽  
Minimum Uncertainty ◽  
Quantum Hydrodynamic ◽  
Transmission Speed

This work shows that in the frame of the stochastic generalization of the quantum hydrodynamic analogy (QHA) the uncertainty principle is fully compatible with the postulate of finite transmission speed of light and information. The theory shows that the measurement process performed in the large scale classical limit in presence of background noise, cannot have a duration smaller than the time need to the light to travel the distance up to which the quantum non-local interaction extend itself. The product of the minimum measuring time multiplied by the variance of energy fluctuation due to presence of stochastic noise shows to lead to the minimum uncertainty principle. The paper also shows that the uncertainty relations can be also derived if applied to the indetermination of position and momentum of a particle of mass m in a quantum fluctuating environment.

A Relativistic Newtonian Mechanics Predicts with Precision the Results of Recent Neutrino-Velocity Experiments

2014 ◽  
Vol 6 (1) ◽  
pp. 1032-1035 ◽  
Author(s):  
Ramzi Suleiman
Keyword(s):  
Null Hypothesis ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Newtonian Mechanics ◽  
Speed Of Light ◽  
Symmetry Principle ◽  
Proposed Model ◽  
Significant Difference ◽  
The One ◽  
Complete Collapse

The research on quasi-luminal neutrinos has sparked several experimental studies for testing the "speed of light limit" hypothesis. Until today, the overall evidence favors the "null" hypothesis, stating that there is no significant difference between the observed velocities of light and neutrinos. Despite numerous theoretical models proposed to explain the neutrinos behavior, no attempt has been undertaken to predict the experimentally produced results. This paper presents a simple novel extension of Newton's mechanics to the domain of relativistic velocities. For a typical neutrino-velocity experiment, the proposed model is utilized to derive a general expression for . Comparison of the model's prediction with results of six neutrino-velocity experiments, conducted by five collaborations, reveals that the model predicts all the reported results with striking accuracy. Because in the proposed model, the direction of the neutrino flight matters, the model's impressive success in accounting for all the tested data, indicates a complete collapse of the Lorentz symmetry principle in situation involving quasi-luminal particles, moving in two opposite directions. This conclusion is support by previous findings, showing that an identical Sagnac effect to the one documented for radial motion, occurs also in linear motion.

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