scholarly journals Exact solutions of Klein–Gordon equations in external electromagnetic fields on 3D de Sitter background

2021 ◽  
Vol 62 (5) ◽  
pp. 053503
Author(s):  
Maria N. Boldyreva ◽  
Alexey A. Magazev
Keyword(s):  
Exact Solutions ◽  
Electromagnetic Fields ◽  
De Sitter ◽  
External Electromagnetic Fields ◽  
Klein Gordon ◽  
Sitter Background

scholarly journals Exact solutions of D-dimensional Klein–Gordon oscillator with Snyder–de Sitter algebra

2020 ◽  
Vol 61 (10) ◽  
pp. 102301
Author(s):  
Zoubir Hemame ◽  
Mokhtar Falek ◽  
Mustafa Moumni
Keyword(s):  
Exact Solutions ◽  
De Sitter ◽  
Klein Gordon

Cosmological expansion and local systems: exact solutions

2008 ◽  
Vol 86 (4) ◽  
pp. 663-667
Author(s):  
V Faraoni
Keyword(s):  
Exact Solutions ◽  
Coupled Systems ◽  
De Sitter ◽  
Strongly Coupled ◽  
New Exact Solutions ◽  
Cosmological Expansion ◽  
Weakly Coupled ◽  
Weakly Coupled Systems ◽  
Sitter Background ◽  
04.20 Jb

We study the competition between cosmological expansion and local attraction for relativistic objects embedded in a generic Friedmann universe. The recently discovered “all or nothing” behaviour (i.e., weakly coupled systems are comoving while strongly coupled ones do not expand at all) is found to be limited to the de Sitter background. New exact solutions are presented describing black holes co-moving with a surrounding universe.PACS Nos.: 98.80.–k,04.20.Jb, 04.20.–q

Schwinger mechanism on de Sitter background

2018 ◽  
Vol 33 (30) ◽  
pp. 1850177 ◽  
Author(s):  
B. Hamil ◽  
M. Merad
Keyword(s):  
Hypergeometric Functions ◽  
Gordon Equation ◽  
Constant Electric Field ◽  
Pair Creation ◽  
Bogoliubov Transformation ◽  
De Sitter ◽  
Klein Gordon ◽  
Sitter Background ◽  
Schwinger Mechanism ◽  
Klein Gordon Equation

In this paper, incorporating the effect of the deformed commutation relation on de Sitter background, we studied the deformed Schwinger mechanism in (1[Formula: see text]+[Formula: see text]1) dimensions for scalars particle of spin-0 in a constant electric field. The Klein–Gordon equation is solved exactly and the wave function is given in term of hypergeometric functions. The canonical method based on a Bogoliubov transformation is applied. The pair creation probability and the density number of created particles are calculated.

Symmetries, conservation laws, reductions, and exact solutions for the Klein–Gordon equation in de Sitter space–times

2012 ◽  
Vol 90 (7) ◽  
pp. 667-674 ◽  
Author(s):  
S. Jamal ◽  
A.H. Kara ◽  
Ashfaque H. Bokhari
Keyword(s):  
Dynamical Systems ◽  
Exact Solutions ◽  
Gordon Equation ◽  
De Sitter Space ◽  
Fundamental Solutions ◽  
De Sitter ◽  
Klein Gordon ◽  
Symmetry Generators ◽  
Math Phys ◽  
Klein Gordon Equation

In this paper, we complement the analysis involving the “fundamental” solutions of the Klein–Gordon equation in de Sitter space–times given by Yagdjian and A. Galstian (Comm. Math. Phys. 285, 293 (2009); Discrete and Continuous Dynamical Systems S, 2(3), 483 (2009)). Using the symmetry generators, we classify and reduce the underlying equations and show how this process may lead to exact solutions by quadratures.

Algebras of symmetry operators of Klein-Gordon-Fock equation for groups acting transitively on two-dimensional subspaces of space-time manifold

2021 ◽  
pp. 126-131
Author(s):  
V.V. Obukhov ◽  
◽  
K.R Myrzakulov ◽  
U.A. Guselnikova ◽  
A. Zhadyranova ◽  
...  
Keyword(s):  
Electromagnetic Fields ◽  
Test Particle ◽  
Dimensional Subspace ◽  
Two Dimensional ◽  
First Order ◽  
External Electromagnetic Fields ◽  
Klein Gordon ◽  
Symmetry Operators ◽  
Charged Test Particle ◽  
Charged Test

All external electromagnetic fields are found in which the Klein-Gordon-Fock equation for a charged test particle admits first-order symmetry operators provided that the groups G 3, r £ 3, of motions act transitively on the two-dimensional subspace V 2.

scholarly journals Algebra of Symmetry Operators for Klein-Gordon-Fock Equation

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 727
Author(s):  
Valeriy V. Obukhov
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Riemannian Space ◽  
Space Time ◽  
First Order ◽  
External Electromagnetic Fields ◽  
Klein Gordon ◽  
Symmetry Operators ◽  
Algebra Of Operators

All external electromagnetic fields in which the Klein-Gordon-Fock equation admits the first-order symmetry operators are found, provided that in the space-time V4 a group of motion G3 acts simply transitively on a non-null subspace of transitivity V3. It is shown that in the case of a Riemannian space Vn, in which the group Gr acts simply transitively, the algebra of symmetry operators of the n-dimensional Klein-Gordon-Fock equation in an external admissible electromagnetic field coincides with the algebra of operators of the group Gr.

scholarly journals Dipole radiation and beyond from axion stars in electromagnetic fields

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Mustafa A. Amin ◽  
Andrew J. Long ◽  
Zong-Gang Mou ◽  
Paul M. Saffin
Keyword(s):  
Electromagnetic Fields ◽  
Parametric Resonance ◽  
Coupling Strength ◽  
Coupling Parameter ◽  
Strong Dependence ◽  
Dipole Radiation ◽  
Large Coupling ◽  
External Electromagnetic Fields ◽  
Order Of Magnitude ◽  
Dimensionless Coupling

Abstract We investigate the production of photons from coherently oscillating, spatially localized clumps of axionic fields (oscillons and axion stars) in the presence of external electromagnetic fields. We delineate different qualitative behaviour of the photon luminosity in terms of an effective dimensionless coupling parameter constructed out of the axion-photon coupling, and field amplitude, oscillation frequency and radius of the axion star. For small values of this dimensionless coupling, we provide a general analytic formula for the dipole radiation field and the photon luminosity per solid angle, including a strong dependence on the radius of the configuration. For moderate to large coupling, we report on a non-monotonic behavior of the luminosity with the coupling strength in the presence of external magnetic fields. After an initial rise in luminosity with the coupling strength, we see a suppression (by an order of magnitude or more compared to the dipole radiation approximation) at moderately large coupling. At sufficiently large coupling, we find a transition to a regime of exponential growth of the luminosity due to parametric resonance. We carry out 3+1 dimensional lattice simulations of axion electrodynamics, at small and large coupling, including non-perturbative effects of parametric resonance as well as backreaction effects when necessary. We also discuss medium (plasma) effects that lead to resonant axion to photon conversion, relevance of the coherence of the soliton, and implications of our results in astrophysical and cosmological settings.

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