scholarly journals Induced fermionic current densities by magnetic flux in higher dimensional cosmic string spacetime

2010 ◽  
Vol 27 (9) ◽  
pp. 095017 ◽  
Author(s):  
Eugênio R Bezerra de Mello
Keyword(s):  
Magnetic Flux ◽  
Cosmic String ◽  
Higher Dimensional ◽  
Current Densities

scholarly journals Induced vacuum bosonic current in a compactified cosmic string spacetime

2016 ◽  
Vol 41 ◽  
pp. 1660117 ◽  
Author(s):  
E. A. F. Bragança ◽  
H. F. Santana Mota ◽  
E. R. Bezerra de Mello
Keyword(s):  
Magnetic Flux ◽  
Cosmic String ◽  
Wave Functions ◽  
Complete Set ◽  
Current Densities

We analyze the bosonic current densities induced by a magnetic flux running along an idealized cosmic string considering that the coordinate along its axis is compactified. We also consider the presence of a magnetic flux enclosed by the compactificatified axis. To develop this analysis, we calculate the complete set of normalized bosonic wave functions obeying a quasiperiodicity condition along the compactified dimension. We show that in this context only the azimuthal and axial currents take place.

scholarly journals Induced vacuum bosonic current by magnetic flux in a higher dimensional compactified cosmic string spacetime

2015 ◽  
Vol 24 (07) ◽  
pp. 1550055 ◽  
Author(s):  
E. A. F. Bragança ◽  
H. F. Santana Mota ◽  
E. R. Bezerra de Mello
Keyword(s):  
Magnetic Flux ◽  
Current Density ◽  
Cosmic String ◽  
Axial Current ◽  
Asymptotic Expressions ◽  
Dimensional Spacetime ◽  
Arbitrary Phase ◽  
Higher Dimensional ◽  
Quantum Flux ◽  
Azimuthal Current

In this paper, we analyze the bosonic current densities induced by a magnetic flux running along an idealized cosmic string in a high-dimensional spacetime, admitting that the coordinate along the string's axis is compactified. Additionally we admit the presence of a magnetic flux enclosed by the compactification axis. In order to develop this analysis we calculate the complete set of normalized bosonic wave functions obeying a quasiperiodicity condition, with arbitrary phase β, along the compactified dimension. In this context, only azimuthal and axial currents densities take place. As to the azimuthal current, two contributions appear. The first contribution corresponds to the standard azimuthal current in a cosmic string spacetime without compactification, while the second contribution is a new one, induced by the compactification itself. The latter is an even function of the magnetic flux enclosed by the string axis and is an odd function of the magnetic flux along its core with period equal to quantum flux, Φ0 = 2π/e. On the other hand, the nonzero axial current density is an even function of the magnetic flux along the core of the string and an odd function of the magnetic flux enclosed by it. We also find that the axial current density vanishes for untwisted and twisted bosonic fields in the absence of the magnetic flux enclosed by the string axis. Some asymptotic expressions for the current density are provided for specific limiting cases of the physical parameter of the model.

Induced fermionic current by a magnetic flux in a cosmic string spacetime at finite temperature

2016 ◽  
Vol 31 (02n03) ◽  
pp. 1641021
Author(s):  
Eugênio R. Bezerra de Mello ◽  
Aram A. Saharian ◽  
Azadeh Mohammadi
Keyword(s):  
Magnetic Flux ◽  
Periodic Function ◽  
Cosmic String ◽  
Finite Temperature ◽  
Chemical Potential ◽  
Vacuum Expectation ◽  
Expectation Values ◽  
Quantum Flux ◽  
Current Densities ◽  
Azimuthal Current

Here we analyze the finite temperature expectation values of the charge and current densities for a massive fermionic quantum field with nonzero chemical potential [Formula: see text], induced by a magnetic flux running along the axis of an idealized cosmic string. These densities are decomposed into the vacuum expectation values and contributions coming from the particles and antiparticles. Specifically the charge density is an even periodic function of the magnetic flux with the period equal to the quantum flux and an odd function of the chemical potential. The only nonzero component of the current density corresponds to the azimuthal current and it is an odd periodic function of the magnetic flux and an even function of the chemical potential. Both analyzed are developed for the cases where [Formula: see text] is smaller than the mass of the field quanta [Formula: see text].

scholarly journals Induced fermionic current in AdS spacetime in the presence of a cosmic string and a compactified dimension

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
S. Bellucci ◽  
W. Oliveira dos Santos ◽  
E. R. Bezerra de Mello
Keyword(s):  
Magnetic Flux ◽  
Cosmic String ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Axial Current ◽  
De Sitter ◽  
Twisted Field ◽  
Compact Dimension ◽  
Ads Spacetime ◽  
Current Densities

AbstractIn this paper, we consider a massive charged fermionic quantum field and investigate the current densities induced by a magnetic flux running along the core of an idealized cosmic string in the background geometry of a 5-dimensional anti-de Sitter spacetime, assuming that an extra dimension is compactified. Along the compact dimension quasi-periodicity condition is imposed on the field with a general phase. Moreover, we admit the presence of a magnetic flux enclosed by the compactified axis. The latter gives rise to Ahanorov–Bohm-like effect on the vacuum expectation value of the currents. In this setup, only azimuthal and axial current densities take place. The former presents two contributions, with the first one due to the cosmic string in a 5-dimensional AdS spacetime without compact dimension, and the second one being induced by the compactification itself. The latter is an odd function of the magnetic flux along the cosmic string and an even function of the magnetic flux enclosed by the compactified axis with period equal to the quantum flux. As to the induced axial current, it is an even function of the magnetic flux along the string’s core and an odd function of the magnetic flux enclosed by the compactification perimeter. For untwisted and twisted field along compact dimension, the axial current vanishes. The massless field case is presented as well some asymptotic limits for the parameters of the model.

scholarly journals VACUUM POLARIZATION OF A CHARGED MASSLESS FERMIONIC FIELD BY A MAGNETIC FLUX IN THE COSMIC STRING SPACETIME

2004 ◽  
Vol 13 (04) ◽  
pp. 607-624 ◽  
Author(s):  
J. SPINELLY ◽  
E. R. BEZERRA DE MELLO
Keyword(s):  
Magnetic Flux ◽  
Cosmic String ◽  
Energy Momentum Tensor ◽  
Finite Thickness ◽  
Momentum Tensor ◽  
Homogeneous Field ◽  
Physical Systems ◽  
Left Handed ◽  
Spinor Fields ◽  
Fermionic Fields

We calculate the vacuum averages of the energy–momentum tensor associated with a massless left-handed spinor fields due to magnetic fluxes on idealized cosmic string spacetime. In this analysis three distinct configurations of magnetic fields are considered: (i) a homogeneous field inside the tube, (ii) a magnetic field proportional to 1/r, and (iii) a cylindrical shell with δ-function. In these three cases the axis of the infinitely long tubes of radius R coincides with the cosmic string. In order to proceed with these calculations we explicitly obtain the Euclidean Feynman propagators associated with these physical systems. As we shall see, these propagators possess two distinct parts. The first are the standard ones, i.e. corresponding to the spinor Green's functions associated with the massless fermionic fields on the idealized cosmic string spacetime with a magnetic flux running through the line singularity. The second parts are new, they are due to the finite thickness of the radius of the tubes. As we shall see these extra parts provide relevant contributions to the vacuum averages of the energy–momentum tensor.

scholarly journals VACUUM POLARIZATION IN A COSMIC STRING SPACETIME INDUCED BY FLAT BOUNDARY

2011 ◽  
Vol 03 ◽  
pp. 434-445
Author(s):  
EUGÊNIO R. BEZERRA DE MELLO ◽  
ARAM A. SAHARIAN
Keyword(s):  
Cosmic String ◽  
Vacuum Polarization ◽  
Energy Momentum Tensor ◽  
Neumann Boundary ◽  
Vacuum Expectation ◽  
Momentum Tensor ◽  
Massive Scalar ◽  
Expectation Values ◽  
Massive Scalar Field ◽  
Higher Dimensional

In this paper we analyze the vacuum expectation values of the field squared and the energy-momentum tensor associated to a massive scalar field in a higher dimensional cosmic string spacetime, obeying Dirichlet or Neumann boundary conditions on the surface orthogonal to the string.

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