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The equation of state for a superconducting cosmic string whose current is due to fermionic zero modes is derived analytically in the case where the back-reaction of the fermions to the background is neglected. It is first shown that the…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Peter , C. Ringeval

We evaluate the Hadamard function and the vacuum expectation value of the current density for a massive complex scalar field in the generalized geometry of a straight cosmic string with a finite core enclosing an arbitrary distributed…

High Energy Physics - Theory · Physics 2015-03-18 E. R. Bezerra de Mello , V. B. Bezerra , A. A. Saharian , H. H. Harutyunyan

A linear magnetic topological defect (cosmic string) is modeled as a magnetic flux-carrying tube that is impenetrable to external spinor matter. The matter field is quantized in the background of this tube, with the most general set of…

High Energy Physics - Theory · Physics 2025-12-09 Yu. I. Pylypchuk , P. O. Nakaznyi , O. V. Barabash , A. O. Zaporozhchenko , V. M. Gorkavenko

Within the context of a bosonized theory, we evaluate the current-current correlation functions corresponding to a massive Dirac field in 2+1 dimensions, which is constrained to a spatial half-plane. We apply the result to the evaluation of…

High Energy Physics - Theory · Physics 2019-09-12 C. D. Fosco , F. A. Schaposnik

The influence of spatial geometry on the vacuum polarization in 2+1-dimensional spinor electrodynamics is investigated. The vacuum angular momentum induced by an external static magnetic field is found to depend on global geometric surface…

High Energy Physics - Theory · Physics 2007-05-23 Yu. A. Sitenko , D. G. Rakityansky

The Hadamard representation of the Green's function of a quantum field on a curved space-time is a powerful tool for computations of renormalized expectation values. We study the Hadamard form of the Feynman Green's function for a massive…

General Relativity and Quantum Cosmology · Physics 2020-04-08 Visakan Balakumar , Elizabeth Winstanley

In the context of the Einstein-Cartan-Dirac model, where the torsion of the space-time couples to the axial currents of the fermions, we study the effects of this quantum-gravitational interaction on a massless neutrino beam crossing…

General Relativity and Quantum Cosmology · Physics 2016-12-21 M. Alimohammadi , A. shariati

We investigate the combined effects of boundaries and topology on the vacuum expectation values (VEVs) of the charge and current densities for a massive 2D fermionic field confined on a conical ring threaded by a magnetic flux. Different…

High Energy Physics - Theory · Physics 2020-04-01 S. Bellucci , I. Brevik , A. A. Saharian , H. G. Sargsyan

In this study, we investigate the fermionic Schwinger effect in the presence of a constant magnetic field within $(1+3)-$dimensional Minkowski spacetime, considering both constant and pulsed electric fields. We analyze the correlations…

High Energy Physics - Theory · Physics 2025-01-28 Shagun Kaushal

In this paper we analyze the relativistic quantum motion of charged spin-0 and spin-1/2 particles in the presence of a uniform magnetic field and scalar potentials in the cosmic string spacetime. In order to develop this analysis, we assume…

High Energy Physics - Theory · Physics 2021-04-12 E. R. Figueiredo Medeiros , E. R. Bezerra de Mello

Exact solutions of the Einstein field equations with cosmic string and space varying cosmological constant, viz., $\Lambda= \Lambda(r)$, in the energy-momentum tensors are presented. Three cases have been studied: where variable…

Astrophysics · Physics 2009-07-22 Saibal Ray , Farook Rahaman , Utpal Mukhopadhyay

In the first part, the induced vacuum spin around an Aharonov-Bohm flux string in massless three-dimensional QED is computed explicitly and the result is shown to agree with a general index theorem. A previous observation in the literature,…

High Energy Physics - Theory · Physics 2015-06-26 Rajesh Parwani

Quantum field theory (QFT) is supposed to be gauge invariant. However it has been well established that a direct calculation of the vacuum polarization tensor produces a non-gauge invariant result. In this paper it will be shown that this…

General Physics · Physics 2017-12-15 Dan Solomon

This work investigates the implications of very special relativity (VSR) on the calculation of vacuum polarization for fermions in the presence of Maxwell and Kalb-Ramond gauge fields in four-dimensional spacetime. We derive the…

High Energy Physics - Theory · Physics 2023-11-16 Roberto V. Maluf , Gonzalo J. Olmo

We study the effect of a background flux string on the vacuum energy of massive Dirac fermions in 2+1 dimensions confined to a finite spatial region through MIT boundary conditions. We treat two admissible self-adjoint extensions of the…

High Energy Physics - Theory · Physics 2009-10-31 C. G. Beneventano , M. De Francia , K. Kirsten , E. M. Santangelo

We study the simultaneous influence of boundary conditions and external fields on quantum fluctuations by considering vacuum zero-point energies for quantum fields in the presence of a magnetic fluxon confined by a bag, circular and…

High Energy Physics - Theory · Physics 2009-10-30 S. Leseduarte , August Romeo

In this paper we evaluate the Wightman functions associated with a massive quantum scalar field in de Sitter and anti-de Sitter spacetimes in the presence of a cosmic string. Having these functions we calculate the corresponding…

High Energy Physics - Theory · Physics 2012-10-03 Eugênio R. Bezerra de Mello

In this paper we study the expectation values of the induced charge and current densities for a massive bosonic field with nonzero chemical potential in the geometry of a higher dimensional compactified cosmic string with magnetic fluxes,…

High Energy Physics - Theory · Physics 2016-06-29 Azadeh Mohammadi , Eugênio Ramos Bezerra de Mello

Cosmic strings produce charged particles which, by emitting electromagnetic radiation, partially ionize neutral hydrogen during the dark ages. Corrections to the ionization fraction of neutral hydrogen induced by cosmic strings could lead…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-05 Samuel Laliberte , Robert Brandenberger

We investigate quantum electrodynamic effects under the influence of an external, time-dependent electromagnetic field, which mediates dynamic modifications of the radiative corrections. Specifically, we consider the quantum electrodynamic…

Atomic Physics · Physics 2013-09-10 A. I. Milstein , I. S. Terekhov , U. D. Jentschura , C. H. Keitel