Vacuum Polarization in the Presence of Magnetic Flux at Finite Temperature in the Cosmic String Background

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].

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Vacuum polarization effects in the cosmic string background

Fortschritte der Physik ◽

10.1002/prop.200900033 ◽

2009 ◽

Vol 57 (5-7) ◽

pp. 705-710

Author(s):

Yu.A. Sitenko ◽

N.D. Vlasii

Keyword(s):

Cosmic String ◽

Vacuum Polarization ◽

Polarization Effects ◽

String Background

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VACUUM POLARIZATION BY A MAGNETIC FLUX TUBE AT FINITE TEMPERATURE IN THE COSMIC STRING SPACE–TIME

International Journal of Modern Physics D ◽

10.1142/s0218271809014273 ◽

2009 ◽

Vol 18 (01) ◽

pp. 53-70 ◽

Cited By ~ 1

Author(s):

J. SPINELLY ◽

E. R. BEZERRA DE MELLO

Keyword(s):

Magnetic Flux ◽

Flux Tube ◽

Cosmic String ◽

Vacuum Polarization ◽

Temperature Limit ◽

Space Time ◽

Magnetic Flux Tube ◽

Massless Scalar ◽

Homogeneous Field ◽

Massless Scalar Field

In this paper, we analyze the effect produced by the temperature in the vacuum polarization associated with a charged massless scalar field in the presence of a magnetic flux tube in the cosmic string space–time. Three different configurations of magnetic fields are taken into account: (i) a homogeneous field inside the tube, (ii) a field proportional to 1/r, and (iii) a cylindrical shell with δ-function. In these three cases, the axis of the infinitely long tube of radius R coincides with the cosmic string. Because of the complexity of this analysis in the region inside the tube, we consider the thermal effect in the region outside. In order to develop this analysis, we construct the thermal Green function associated with this system for the three above-mentioned situations considering points in the region outside the tube. We explicitly calculate, in the high-temperature limit, the thermal average of the field square and the energy–momentum tensor.

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VACUUM POLARIZATION BY FERMIONIC FIELDS IN HIGHER DIMENSIONAL COSMIC STRING SPACE-TIME

International Journal of Modern Physics A ◽

10.1142/s0217751x09044851 ◽

2009 ◽

Vol 24 (08n09) ◽

pp. 1481-1488 ◽

Cited By ~ 4

Author(s):

J. SPINELLY ◽

E. R. BEZERRA DE MELLO

Keyword(s):

Magnetic Flux ◽

Cosmic String ◽

Vacuum Polarization ◽

Fractional Part ◽

Vacuum Expectation ◽

Vacuum Expectation Value ◽

Momentum Tensor ◽

Closed Expression ◽

Fermionic Fields ◽

Tensor Formula

In this paper we investigate vacuum polarization effects associated with charged massive quantum fermionic fields in a six-dimensional cosmic string space-times considering the presence of a magnetic flux running along its core. We have shown that for specific values of the parameters which codify the presence of the cosmic string, and the fractional part of the ratio of the magnetic flux by the quantum one, a closed expression for the respective Green function is obtained. Adopting this result, we explicitly calculate the renormalized vacuum expectation value of the energy-momentum tensor, [Formula: see text], and analyse this result in some limiting cases.

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