scholarly journals Scalar Radiation in Interaction of Cosmic String with Point Charge

Universe ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 206
Author(s):  
Pavel Spirin
Keyword(s):  
Cosmic String ◽  
Relativistic Particle ◽  
Casimir Effect ◽  
Angular Distributions ◽  
Destructive Interference ◽  
Radiation Emission ◽  
Physical Problems ◽  
Radiation Amplitude ◽  
Non Local ◽  
Newtonian Constant

We consider the scalar bremsstrahlung of the spinless relativistic particle, which interacts with infinitely thin cosmic string by linearized gravity. With the iterational scheme, based on the Perturbaion Theory with respect to the Newtonian constant, we compute the radiation amplitude and the emitted energy due to collision. The general phenomenon of mutual cancellation of the leading terms on the local and non-local amplitude, known in the ultrarelativistic regime for several types of collision, also takes place here. Remarkably, this cancellation (destructive interference) is complete, and takes place for any particle’s velocity. We compute the spectral and angular distributions of the emitted waves. Particular attention is paid to the ultrarelativistic case. Due to the radiation emission, a string may lose its energy and decrease the tension; it may affect all field effects, including the vacuum polarization and the Casimir effect, in terms of physical problems with the real cosmic strings.

SOLUTION OF THE DIRAC EQUATION WITH POSITION-DEPENDENT MASS IN A COULOMB AND SCALAR FIELDS IN A CONICAL SPACETIME

2013 ◽  
Vol 28 (31) ◽  
pp. 1350137 ◽  
Author(s):  
GEUSA DE A. MARQUES ◽  
V. B. BEZERRA ◽  
SHI-HAI DONG
Keyword(s):  
Dirac Equation ◽  
Cosmic String ◽  
Relativistic Particle ◽  
Energy Levels ◽  
Scalar Potential ◽  
Scalar Fields ◽  
The Self ◽  
Dependent Mass ◽  
Scalar Potentials ◽  
Position Dependent Mass

We consider the problem of a relativistic particle with position-dependent mass in the presence of a Coulomb and a scalar potentials in the background spacetime generated by a cosmic string. The scalar potential arises from the self-interaction potential which is induced by the conical geometry of the spacetime under consideration. We find the solution of the corresponding Dirac equation and determine the energy spectrum of the particle. The behavior of the energy levels on the parameters associated with the presence of the cosmic string and with the fact that the mass of the particle depends on its position is also analyzed.

The study of a spinless relativistic particle in the spinning cosmic string space–time

2017 ◽  
Vol 95 (4) ◽  
pp. 331-335 ◽  
Author(s):  
Zhi Wang ◽  
Zheng-wen Long ◽  
Chao-yun Long ◽  
Bing-qian Wang
Keyword(s):  
Cosmic String ◽  
Gordon Equation ◽  
Relativistic Particle ◽  
Energy Levels ◽  
Space Time ◽  
Rotational Parameter ◽  
Cylindrically Symmetric ◽  
Background Space ◽  
Klein Gordon ◽  
Klein Gordon Equation

In this paper we analyze a spinless relativistic particle depicted by the Klein–Gordon equation in the spinning cosmic string space–time. The solutions of the Klein–Gordon equation in the presence of a uniform magnetic field and the Klein–Gordon equation with two common cylindrically symmetric scalar potentials under the background space–time are presented; the energy spectrum and the corresponding wave functions of these systems are obtained by using the functional analysis method. It is shown that the energy levels of the considered physical systems depend explicitly on the angular deficit α and the rotational parameter a, which characterize the global structure of the metric in the space–time of the spinning cosmic string.

scholarly journals Effects of Quantum Fields Outside Cosmic Strings

1988 ◽  
Vol 130 ◽  
pp. 565-565
Author(s):  
D. A. Konkowski ◽  
T. M. Helliwell
Keyword(s):  
Cosmic String ◽  
Casimir Effect ◽  
Semiclassical Approximation ◽  
Mass Density ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Energy Tensor ◽  
Parallel Plates ◽  
Vacuum Fluctuations ◽  
Gravitational Influence

The space surrounding a long straight cosmic string is flat but conical. The conical topology implies that such a string focuses light rays or particles passing by opposite sides of the string, which can have important astrophysical effects. The flatness, however, implies that the string has no gravitational influence on matter at rest with respect to the string. The flatness is a consequence of the fact that the tension along a cosmic string is equal to its linear mass density μ. There may be physical effects, however, which destroy the equality of tension and mass density, so that straight strings might after all affect matter at rest. One such effect we and others have calculated is the vacuum fluctuations of fields near the strings induced by the conical topology. Such fluctuation s are physically observable but normally small, as in the Casimir effect between parallel plates. We find the vacuum expectation value of the stress - energy tensor of a conformally coupled scalar field around a cosmic string to be in cylindrical coordinates (t, r, θ, z). The equality of Ttt and Tzz means that the effective tension and mass density of the vacuum fluctuations are equal, so that at least in a semiclassical approximation a string dressed by such fields still has no gravitational influence on matter at rest, even though it has a substantial mass density.

Remarks on a gravitational analogue of the Casimir effect

2016 ◽  
Vol 25 (09) ◽  
pp. 1641018 ◽  
Author(s):  
V. B. Bezerra ◽  
H. F. Mota ◽  
C. R. Muniz
Keyword(s):  
Scalar Field ◽  
Cosmic String ◽  
Vacuum Energy ◽  
Casimir Effect ◽  
String Tension ◽  
Casimir Energy ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Quantum Field ◽  
Einstein Universe

We consider the Casimir effect, by calculating the Casimir energy and its corrections for nonzero temperatures, of a massless scalar field in the spacetime with topology [Formula: see text] (Einstein universe) containing an idealized cosmic string. The obtained results confirm the role played by the identifications imposed on the quantum field by boundary conditions arising from the topology of the gravitational field under consideration and illustrate a realization of a gravitational analogue of the Casimir effect. In this backgorund, we show that the vacuum energy can be written as a term which corresponds to the vacuum energy of the massless scalar field in the Einstein universe added by another term that formally corresponds to the vacuum energy of the electromagnetic field in the Einstein universe, multiplied by a parameter associated with the presence of the cosmic string, namely, [Formula: see text], where [Formula: see text] is a constant related to the cosmic string tension, [Formula: see text].

scholarly journals Gravitational Interaction of Cosmic String with Spinless Particle

Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 184
Author(s):  
Pavel Spirin
Keyword(s):  
Cosmic String ◽  
Particle Motion ◽  
Relativistic Particle ◽  
Gravitational Interaction ◽  
Spinless Particle ◽  
Linearized Theory ◽  
Theory Framework

We consider the gravitational interaction of spinless relativistic particle and infinitely thin cosmic string within the classical linearized-theory framework. We compute the particle’s motion in the transverse (to the unperturbed string) plane. The reciprocal action of the particle on the cosmic string is also investigated. We derive the retarded solution which includes the longitudinal (with respect to the unperturbed-particle motion) and totally-transverse string perturbations.

scholarly journals Topological Casimir effect in compactified cosmic string spacetime

2012 ◽  
Vol 29 (3) ◽  
pp. 035006 ◽  
Author(s):  
E R Bezerra de Mello ◽  
A A Saharian
Keyword(s):  
Cosmic String ◽  
Casimir Effect
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