scholarly journals Classicalization of quantum fluctuations at the Planck scale in the Rh = ct universe

2021 ◽  
pp. 136362
Author(s):  
Fulvio Melia
Keyword(s):  
Planck Scale ◽  
Quantum Fluctuations

scholarly journals SMOOTHED QUANTUM FLUCTUATIONS AND CMB OBSERVATIONS

2012 ◽  
Vol 21 (10) ◽  
pp. 1250080
Author(s):  
JAKUB MIELCZAREK ◽  
MICHAŁ KAMIONKA
Keyword(s):  
Scalar Field ◽  
Power Spectrum ◽  
Internal Structure ◽  
Planck Scale ◽  
Quantum Fluctuations ◽  
Gaussian Smoothing ◽  
Cosmic Inflation ◽  
Smoothing Factor ◽  
High Multipoles

In this paper, we investigate power spectrum of a smoothed scalar field. The smoothing leads to regularization of the UV divergences and can be related with the internal structure of the considered field or the space itself. We perform Gaussian smoothing to the quantum fluctuations generated during the phase of cosmic inflation. We study whether this effect can be probed observationally and conclude that the modifications of the power spectrum due to the smoothing on the Planck scale are negligible and far beyond the observational abilities. Subsequently, we investigate whether smoothing in any other form can be probed observationally. We introduce phenomenological smoothing factor e-k2σ2 to the inflationary spectrum and investigate its effects on the spectrum of CMB anisotropies and polarization. We show that smoothing can lead to suppression of high multipoles in the spectrum of the CMB. Based on seven years observations of WMAP satellite we indicate that the present scale of high multipoles suppression is constrained by σ < 3.19 Mpc (95% CL). This corresponds to the constraint σ < 100 μm at the end of inflation. Despite this value is far above the Planck scale, other processes of smoothing can be possibly studied with this constraint, as decoherence or diffusion of primordial perturbations.

SQUEEZED QUANTUM STATE IN INFLATION WITH TRANS-PLANCKIAN CUTOFF

2004 ◽  
Vol 19 (13n16) ◽  
pp. 1223-1226 ◽  
Author(s):  
SEOKTAE KOH
Keyword(s):  
Dispersion Relation ◽  
Quantum State ◽  
Particle Production ◽  
Planck Scale ◽  
Quantum Fluctuations ◽  
Quantum States ◽  
Planck Scale Physics

The fields, created from quantum fluctuations during inflation era, are known to be in squeezed quantum states. And recent studies show that the Planck scale physics can have observable cosmological effects. We investigate here how the squeezed quantum states are influenced by the trans-Planckian cutoff which modifies the dispersion relation on subhorizon scales, and calculate the particle production at the end of the inflation.

scholarly journals Spacetime Foam, Midisuperspace, and the Cosmological Constant

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 495
Author(s):  
Steven Carlip
Keyword(s):  
Cosmological Constant ◽  
Time Evolution ◽  
Planck Scale ◽  
Quantum Fluctuations ◽  
Spacetime Foam

Perhaps the cosmological constant really is huge at the Planck scale, but is “hidden” by Planck scale quantum fluctuations of spacetime. I briefly review this proposal and provide some evidence, coming from a simplified midisuperspace model, that an appropriate “foamy” structure can do the job of hiding a large cosmological constant, and can persist under time evolution.

scholarly journals Classicalization of Quantum Fluctuations at the Planck Scale in the Rh=ct Universe

2021 ◽  
Author(s):  
FULVIO MELIA
Keyword(s):  
Degrees Of Freedom ◽  
Field Potential ◽  
Planck Scale ◽  
Quantum Fluctuations ◽  
Harmonic Oscillators ◽  
New Developments ◽  
Active Mass ◽  
Primordial Power Spectrum ◽  
Classical Transition ◽  
Planck Time

Abstract The quantum to classical transition of fluctuations in the early universe is still not completely understood. Some headway has been made incorporating the effects of decoherence and the squeezing of states, though the methods and procedures continue to be challenged. But new developments in the analysis of the most recent Planck data suggest that the primordial power spectrum has a cutoff associated with the very first quantum fluctuation to have emerged into the semi-classical universe from the Planck domain at about the Planck time. In this paper, we examine the implications of this result on the question of classicalization, and demonstrate that the birth of quantum fluctuations at the Planck scale would have been a `process' supplanting the need for a `measurement' in quantum mechanics. Emerging with a single wavenumber, these fluctuations would have avoided the interference between different degrees of freedom in a superposed state. Moreover, the implied scalar field potential had an equation-of-state consistent with the zero active mass condition in general relativity, allowing the quantum fluctuations to emerge in their ground state with a time-independent frequency. They were therefore effectively quantum harmonic oscillators with classical correlations in phase space from the very beginning.

scholarly journals A limit on Planck-scale froth with ESPRESSO

2020 ◽  
Vol 494 (4) ◽  
pp. 4884-4890
Author(s):  
Ryan Cooke ◽  
Louise Welsh ◽  
Michele Fumagalli ◽  
Max Pettini
Keyword(s):  
Monochromatic Light ◽  
Continuous Distribution ◽  
Planck Scale ◽  
Quantum Fluctuations ◽  
Space Time ◽  
Step Size ◽  
Initial State ◽  
New Formalism ◽  
Very Large Telescope ◽  
Gas Cloud

ABSTRACT Some models of quantum gravity predict that the very structure of space–time is ‘frothy’ due to quantum fluctuations. Although the effect is expected to be tiny, if these space–time fluctuations grow over a large distance, the initial state of a photon, such as its energy, is gradually washed out as the photon propagates. Thus, in these models, even the most monochromatic light source would gradually disperse in energy due to space–time fluctuations over large distances. In this paper, we use science verification observations obtained with ESPRESSO at the Very Large Telescope to place a novel bound on the growth of space–time fluctuations. To achieve this, we directly measure the width of a narrow Fe ii absorption line produced by a quiescent gas cloud at redshift $z$ ≃ 2.34, corresponding to a comoving distance of ≃5.8 Gpc. Using a heuristic model where the energy fluctuations grow as σE/E = (E/EP)α, where EP ≃ 1.22 × 1028 eV is the Planck energy, we rule out models with α ≤ 0.634, including models where the quantum fluctuations grow as a random walk process (α = 0.5). Finally, we present a new formalism where the uncertainty accrued at discrete space–time steps is drawn from a continuous distribution. We conclude, if photons take discrete steps through space–time and accumulate Planck-scale uncertainties at each step, then our ESPRESSO observations require that the step size must be at least ≳ 1013.2lP, where lP is the Planck length.

Quantum fluctuations have been shown to affect macroscopic objects

Nature ◽  
2020 ◽  
Vol 583 (7814) ◽  
pp. 31-32
Author(s):  
Valeria Sequino ◽  
Mateusz Bawaj
Keyword(s):  
Quantum Fluctuations ◽  
Macroscopic Objects

Quantum fluctuations in magnetic nanostructures

2018 ◽  
Vol 189 (01) ◽  
pp. 85-94
Author(s):  
Yuri N. Barabanenkov ◽  
Sergej A. Nikitov ◽  
Mikhail Yu. Barabanenkov
Keyword(s):  
Magnetic Nanostructures ◽  
Quantum Fluctuations

Thermodynamics of the singularity of a black hole and the mass of the rebound

2020 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Equilibrium Condition ◽  
Planck Scale

In this paper, we analyze the singularity of a black hole based on a modification of general relativity. There is an equilibrium condition on the Planck scale. This makes it possible to study the thermodynamics of the singularity of a black hole.

scholarly journals Renormalization group equations of Higgs-R2 inflation

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Yohei Ema ◽  
Kyohei Mukaida ◽  
Jorinde van de Vis
Keyword(s):  
Renormalization Group ◽  
Standard Model ◽  
Planck Scale ◽  
Energy Scale ◽  
Einstein Frame ◽  
Ricci Scalar ◽  
Minimal Coupling ◽  
Renormalization Group Equations ◽  
The Standard Model

Abstract We derive one- and two-loop renormalization group equations (RGEs) of Higgs-R2 inflation. This model has a non-minimal coupling between the Higgs and the Ricci scalar and a Ricci scalar squared term on top of the standard model. The RGEs derived in this paper are valid as long as the energy scale of interest (in the Einstein frame) is below the Planck scale. We also discuss implications to the inflationary predictions and the electroweak vacuum metastability.

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