scholarly journals Vacuum bosonic currents induced by a compactified cosmic string in dS background

2020 ◽  
Vol 29 (15) ◽  
pp. 2050103
Author(s):  
E. A. F. Bragança ◽  
E. R. Bezerra de Mello ◽  
A. Mohammadi
Keyword(s):  
Cosmic String ◽  
Axial Current ◽  
Wave Functions ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Fermionic Field ◽  
Sitter Spacetime ◽  
Compact Dimension ◽  
Complete Set ◽  
Current Densities

In this paper, we study the vacuum bosonic currents in the geometry of a compactified cosmic string in the background of the de Sitter spacetime. The currents are induced by magnetic fluxes, one running along the cosmic string and another one enclosed by the compact dimension. To develop the analysis, we obtain the complete set of normalized bosonic wave functions obeying a quasiperiodicity condition. In this context, we calculate the azimuthal and axial current densities and we show that these quantities are explicitly decomposed into two contributions: one originating from the geometry of a straight uncompactified cosmic string and the other induced by the compactification. We also compare the results with the literature in the case of a massive fermionic field in the same geometry.

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.

MACROSCOPICITY AND CLASSICALITY OF QUANTUM FLUCTUATIONS IN DE SITTER SPACE

1988 ◽  
Vol 03 (10) ◽  
pp. 929-940 ◽  
Author(s):  
SUMIO WADA
Keyword(s):  
Quantum Mechanics ◽  
Quantum Fluctuations ◽  
Quantum States ◽  
Wave Functions ◽  
Interpretation Of Quantum Mechanics ◽  
De Sitter Spacetime ◽  
Probabilistic Interpretation ◽  
De Sitter ◽  
Sitter Spacetime ◽  
Matter Fields

On the basis of the non-probabilistic interpretation of quantum mechanics, we define “macroscopicity” and “classicality” of quantum fluctuations as closely related but separate concepts. Then these properties are examined in quantum states (wave functions) of matter fields in de Sitter spacetime.

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 Fermionic vacuum polarization by a cosmic string in anti-de Sitter spacetime

2013 ◽  
Vol 30 (17) ◽  
pp. 175001 ◽  
Author(s):  
E R Bezerra de Mello ◽  
E R Figueiredo Medeiros ◽  
A A Saharian
Keyword(s):  
Cosmic String ◽  
Vacuum Polarization ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime

scholarly journals WORMHOLES IN SPACETIMES WITH COSMOLOGICAL HORIZONS

1999 ◽  
Vol 08 (03) ◽  
pp. 325-335 ◽  
Author(s):  
CARLOS BARCELÓ
Keyword(s):  
Cosmological Constant ◽  
Wave Functions ◽  
Low Energy ◽  
De Sitter Spacetime ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Effective Interactions ◽  
Energy Field ◽  
Flat Spacetime ◽  
Sitter Spacetime

A generalization of the asymptotic wormhole boundary condition for the case of spacetimes with a cosmological horizon is proposed. In particular, we consider de Sitter spacetime with small cosmological constant. The wave functions selected by this proposal are exponentially damped in WKB approximation when the scale factor is large but still much smaller than the horizon size. In addition, they only include outgoing gravitational modes in the region beyond the horizon. We argue that these wave functions represent quantum wormholes and compute the local effective interactions induced by them in low-energy field theory. These effective interactions differ from those for flat spacetime in terms that explicitly depend on the cosmological constant.

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