CREATION OF SCALAR AND DIRAC PARTICLES IN THE PRESENCE OF A TIME VARYING ELECTRIC FIELD IN AN ANISOTROPIC UNIVERSE

2002 ◽  
Vol 17 (20) ◽  
pp. 2781-2781
Author(s):  
VÍCTOR M. VILLALBA
Keyword(s):  
Electric Field ◽  
Particle Distribution ◽  
Anisotropic Universe ◽  
Homogeneous Electric Field ◽  
Dirac Equations ◽  
Dirac Particles ◽  
Electric Interaction ◽  
Quasiclassical Limit ◽  
Klein Gordon ◽  
Hamilton Jacobi Equation

We compute the density of scalar and Dirac particles created by a cosmological anisotropic universe1,2 in the presence of a time dependent homogeneous electric field. In order to compute the rate of particles created we apply a quasiclassical approach that has been used successfully in different scenarios3,4. The idea behind the method is the following: First, we solve the relativistic Hamilton-Jacobi equation and, looking at its solutions, we identify positive and negative frequency modes. Second, after separating variables5,6, we solve the Klein-Gordon and Dirac equations and, after comparing with the results obtained for the quasiclassical limit, we identify the positive and negative frequency states. We show that the particle distribution becomes thermal when one neglects the electric interaction.

scholarly journals CREATION OF DIRAC PARTICLES IN THE PRESENCE OF A CONSTANT ELECTRIC FIELD IN AN ANISOTROPIC BIANCHI I UNIVERSE

2002 ◽  
Vol 17 (28) ◽  
pp. 1883-1891 ◽  
Author(s):  
VÍCTOR M. VILLALBA ◽  
WALTER GREINER
Keyword(s):  
Electric Field ◽  
Particle Distribution ◽  
Constant Electric Field ◽  
Dirac Particles ◽  
Bianchi I ◽  
Electric Interaction

In this article we compute the density of Dirac particles created by a cosmological anisotropic Bianchi I universe in the presence of a constant electric field. We show that the particle distribution becomes thermal when one neglects the electric interaction.

scholarly journals KLEIN–GORDON AND DIRAC PARTICLES IN NONCONSTANT SCALAR-CURVATURE BACKGROUND

2008 ◽  
Vol 23 (10) ◽  
pp. 1613-1626 ◽  
Author(s):  
M. ALIMOHAMMADI ◽  
A. A. BAGHJARY
Keyword(s):  
Transverse Momentum ◽  
Scalar Curvature ◽  
Discrete Spectrum ◽  
Ground State ◽  
State Energy ◽  
Geometrical Properties ◽  
Dirac Equations ◽  
Dirac Particles ◽  
Klein Gordon ◽  
Energy Formula

The Klein–Gordon and Dirac equations are considered in a semiinfinite laboratory (x > 0) in the presence of background metrics ds2 = u2(x)ημν dxμ dxν and ds2 = -dt2 + u2(x)ηij dxi dxj with u(x) = e±gx. These metrics have nonconstant scalar-curvatures. Various aspects of the solutions are studied. For the first metric with u(x) = egx, it is shown that the spectra are discrete, with the ground state energy [Formula: see text] for spin-0 particles. For u(x) = e-gx, the spectrums are found to be continuous. For the second metric with u(x) = e-gx, each particle, depends on its transverse-momentum, can have continuous or discrete spectrum. For Klein–Gordon particles, this threshold transverse-momentum is [Formula: see text], while for Dirac particles it is g/2. There is no solution for u(x) = egx case. Some geometrical properties of these metrics are also discussed.

scholarly journals Quantum Probes of Timelike Naked Singularities in2+1-Dimensional Power-Law Spacetimes

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
O. Gurtug ◽  
M. Halilsoy ◽  
S. Habib Mazharimousavi
Keyword(s):  
Quantum Mechanics ◽  
Scalar Field ◽  
Electric Field ◽  
Power Law ◽  
Energy Conditions ◽  
Naked Singularities ◽  
Real Scalar ◽  
Dirac Equations ◽  
Klein Gordon ◽  
Scalar Theories

The formation of naked singularities in2+1-dimensional power-law spacetimes in linear Einstein-Maxwell and Einstein-scalar theories sourced by azimuthally symmetric electric field and a self-interacting real scalar field, respectively, are considered in view of quantum mechanics. Quantum test fields obeying the Klein-Gordon and Dirac equations are used to probe the classical timelike naked singularities developed atr=0. We show that when the classically singular spacetimes probed with scalar waves, the considered spacetimes remain singular. However, the spinorial wave probe of the singularity in the metric of a self-interacting real scalar field remains quantum regular. The notable outcome in this study is that the quantum regularity/singularity cannot be associated with the energy conditions.

scholarly journals QUANTUM SINGULARITIES IN STATIC SPACETIMES

2011 ◽  
Vol 20 (05) ◽  
pp. 729-743 ◽  
Author(s):  
JOÃO PAULO M. PITELLI ◽  
PATRICIO S. LETELIER
Keyword(s):  
Quantum Mechanics ◽  
Wave Operator ◽  
Point Of View ◽  
Quantum Mechanical ◽  
Mathematical Framework ◽  
Physical Content ◽  
Dirac Equations ◽  
Quantum Particles ◽  
Klein Gordon ◽  
Quantum Singularities

We review the mathematical framework necessary to understand the physical content of quantum singularities in static spacetimes. We present many examples of classical singular spacetimes and study their singularities by using wave packets satisfying Klein–Gordon and Dirac equations. We show that in many cases the classical singularities are excluded when tested by quantum particles but unfortunately there are other cases where the singularities remain from the quantum mechanical point of view. When it is possible we also find, for spacetimes where quantum mechanics does not exclude the singularities, the boundary conditions necessary to turn the spatial portion of the wave operator to be self-adjoint and emphasize their importance to the interpretation of quantum singularities.

SOLITARY WAVES OF THE NONLINEAR KLEIN-GORDON EQUATION COUPLED WITH THE MAXWELL EQUATIONS

2002 ◽  
Vol 14 (04) ◽  
pp. 409-420 ◽  
Author(s):  
VIERI BENCI ◽  
DONATO FORTUNATO FORTUNATO
Keyword(s):  
Electromagnetic Field ◽  
Solitary Wave ◽  
Electric Field ◽  
Solitary Waves ◽  
Maxwell Equations ◽  
Gordon Equation ◽  
Klein Gordon ◽  
Klein Gordon Equation

This paper is divided in two parts. In the first part we construct a model which describes solitary waves of the nonlinear Klein-Gordon equation interacting with the electromagnetic field. In the second part we study the electrostatic case. We prove the existence of infinitely many pairs (ψ, E), where ψ is a solitary wave for the nonlinear Klein-Gordon equation and E is the electric field related to ψ.

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