scholarly journals On quantum corrections to geodesics in de-Sitter spacetime

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Viacheslav A. Emelyanov
Keyword(s):  
Wave Packet ◽  
Gordon Equation ◽  
Plane Waves ◽  
Hubble Constant ◽  
De Sitter ◽  
Field Mass ◽  
Sitter Spacetime ◽  
Klein Gordon ◽  
De Sitter Universe ◽  
Positive Frequency

AbstractWe find a coordinate-independent wave-packet solution of the massive Klein–Gordon equation with the conformal coupling to gravity in the de-Sitter universe. This solution can locally be represented through the superposition of positive-frequency plane waves at any space-time point, assuming that the scalar-field mass M is much bigger than the de-Sitter Hubble constant H. The solution is also shown to be related to the two-point function in the de-Sitter quantum vacuum. Moreover, we study the wave-packet propagation over cosmological times, depending on the ratio of M and H. In doing so, we find that this wave packet propagates like a point-like particle of the same mass if $$M \ggg H$$ M ⋙ H , but, if otherwise, the wave packet behaves highly non-classically.

FRACTIONAL ANALYSIS OF WAVE PACKET PROPAGATION AND SOME ASPECTS OF VSL WITH GUP

Fractals ◽  
2008 ◽  
Vol 16 (01) ◽  
pp. 33-42 ◽  
Author(s):  
S. HAMID MEHDIPOUR ◽  
KOUROSH NOZARI ◽  
S. DAVOOD SADATIAN
Keyword(s):  
Wave Packet ◽  
Gordon Equation ◽  
Generalized Uncertainty Principle ◽  
De Sitter ◽  
Modified Dispersion Relation ◽  
Fractional Analysis ◽  
Klein Gordon ◽  
De Sitter Universe ◽  
Klein Gordon Equation ◽  
Wave Packet Broadening

In this paper, we consider the problem of wave packet broadening in the framework of the Generalized Uncertainty Principle (GUP) of quantum gravity. Then we find a fractal Klein-Gordon equation to further analyze the wave packet broadening in a foamy spacetime. We derive a Modified Dispersion Relation (MDR) in the context of GUP which shows an extra broadening due to gravitational induced uncertainty. As a result of these dispersion relations, a generalized Klein-Gordon equation can be obtained. We solve this generalized equation under certain conditions to find both analytical and numerical results. We show that GUP can lead to a variation of the fundamental constants such as speed of light. With this novel properties, we find a time-dependent equation of state for perfect fluid in de Sitter universe and we interpret its physical implications.

scholarly journals AMPLITUDE OF COULOMB SCATTERING FOR CHARGED SCALAR FIELD IN DE SITTER SPACETIME

2010 ◽  
Vol 25 (20) ◽  
pp. 1679-1687 ◽  
Author(s):  
COSMIN CRUCEAN
Keyword(s):  
Scalar Field ◽  
Gordon Equation ◽  
Coulomb Scattering ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Scattering Process ◽  
Charged Scalar ◽  
Sitter Spacetime ◽  
Klein Gordon ◽  
Charged Scalar Field

The scattering of a charged scalar field on Coulomb potential is studied using solutions of the Klein–Gordon equation which have a definite momentum. One obtains that the modulus of momentum is not conserved in the scattering process on de Sitter space.

scholarly journals Approximate solutions to the nonlinear Klein-Gordon equation in de Sitter spacetime

Open Physics ◽  
2016 ◽  
Vol 14 (1) ◽  
pp. 314-320 ◽  
Author(s):  
Muhammet Yazici ◽  
Süleyman Şengül
Keyword(s):  
Gordon Equation ◽  
Variational Iteration Method ◽  
Approximate Solutions ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Initial Value ◽  
Transform Method ◽  
Sitter Spacetime ◽  
Klein Gordon ◽  
Klein Gordon Equation

AbstractWe consider initial value problems for the nonlinear Klein-Gordon equation in de Sitter spacetime. We use the differential transform method for the solution of the initial value problem. In order to show the accuracy of results for the solutions, we use the variational iteration method with Adomian’s polynomials for the nonlinearity. We show that the methods are effective and useful.

scholarly journals NEW SPHERICAL SCALAR MODES ON THE DE SITTER EXPANDING UNIVERSE

2012 ◽  
Vol 27 (23) ◽  
pp. 1250124 ◽  
Author(s):  
GABRIEL PASCU
Keyword(s):  
Plane Wave ◽  
Time Evolution ◽  
Gordon Equation ◽  
Expanding Universe ◽  
De Sitter ◽  
Coordinate Chart ◽  
Sitter Spacetime ◽  
Klein Gordon ◽  
Klein Gordon Equation ◽  
Wave Modes

New spherical scalar modes on the expanding part of Sitter spacetime, eigenfunctions of a conserved Hamiltonian-like operator are found by solving the Klein–Gordon equation in the appropriate coordinate chart, with the help of a time evolution picture technique specially developed for spatially flat Friedmann–Lemaître–Robertson–Walker (FLRW) charts. Transition coefficients are computed between these modes and the rest of the scalar spherical and plane wave modes, either momentum or energy eigenfunctions on the spatially flat FLRW chart.

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