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In this paper, we investigate the vacuum bosonic current density induced by a carrying-magnetic-flux cosmic string in a $(D+1)$-de Sitter spacetime considering the presence of two flat boundaries perpendicular to it. In this setup, the…

High Energy Physics - Theory · Physics 2024-12-05 W. Oliveira dos Santos , H. F. Santana Mota , E. R. Bezerra de Mello

In this work we compute the vacuum expectation values of the energy-momentum tensor and the average value of a massive, charged scalar field in the presence of a magnetic flux cosmic string for both zero- and finite-temperature cases.

High Energy Physics - Theory · Physics 2009-11-10 M. E. X. Guimaraes , A. L. N. Oliveira

It is well-known that some physical effects may arise in the spacetime of a straigth cosmic string due to its global conic properties. Among these effects, the vacuum polarization effect has been extensively studied in the litterature. In…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. E. X. Guimaraes

We study massive spinor fields in the geometry of a straight cosmic string in a de Sitter background. We find a hidden N=2 supersymmetry in the fermionic solutions of the equations of motion. We connect the zero mode solutions to the…

High Energy Physics - Theory · Physics 2015-05-27 V. K. Oikonomou

Vacuum expectation values of the energy-momentum tensor for a conformally coupled scalar field is investigated in de Sitter (dS) spacetime in presence of a curved brane on which the field obeys the Robin boundary condition with coordinate…

High Energy Physics - Theory · Physics 2009-11-10 A. A. Saharian , M. R. Setare

The electromagnetic field correlators are evaluated around a cosmic string in background of $(D+1)$-dimensional dS spacetime assuming that the field is prepared in the Bunch-Davies vacuum state. The correlators are presented in the…

High Energy Physics - Theory · Physics 2017-08-01 A. A. Saharian , V. F. Manukyan , N. A. Saharyan

Fermionic condensate and the vacuum expectation values of the energy-momentum tensor are investigated for a massive spinor fields in higher-dimensional spacetimes with an arbitrary number of toroidally compactified spatial dimensions. By…

High Energy Physics - Theory · Physics 2010-02-08 S. Bellucci , A. A. Saharian

We analyze the Casimir densities and forces associated with a massive scalar quantum field confined between two parallel plates in a D-dimensional cosmic string spacetime. The plates are placed orthogonal to the string and the field obeys…

High Energy Physics - Theory · Physics 2018-05-03 E. R. Bezerra de Mello , A. A. Saharian , S. V. Abajyan

Making use of the symmetries of anti-de Sitter space-time, we derive an analytic expression for the bispinor of parallel transport, from which we construct in closed form the vacuum Feynman Green's function of the Dirac field on this…

High Energy Physics - Theory · Physics 2019-03-15 Victor E. Ambrus , Elizabeth Winstanley

We investigate vacuum expectation value of the energy-momentum tensor for a massive Dirac field in flat spacetime with a toroidal subspace of a general dimension. Quasiperiodicity conditions with arbitrary phases are imposed on the field…

High Energy Physics - Theory · Physics 2024-08-09 A. A. Saharian , R. M. Avagyan , G. H. Harutyunyan , G. H. Nikoghosyan

Fermionic condensate is investigated in $(D+1)$-dimensional de Sitter spacetime by using the cutoff function regularization. In order to fix the renormalization ambiguity for massive fields an additional condition is imposed, requiring the…

High Energy Physics - Theory · Physics 2021-12-01 A. A. Saharian , E. R. Bezerra de Mello , A. S. Kotanjyan , T. A. Petrosyan

In 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…

High Energy Physics - Theory · Physics 2020-11-17 S. Bellucci , W. Oliveira dos Santos , E. R. Bezerra de Mello

In this paper we analyse the vacuum fluctuations of quantum fermionic current densities, $<j^A(x)>$, induced by a magnetic flux running along the core of the conical space produced by the presence of cosmic string, in a $(1+d)-$dimensional…

High Energy Physics - Theory · Physics 2014-11-20 E. R. Bezerra de Mello

We investigate the vacuum polarization effects associated with a charged massless spin-1/2 field in a higher-dimensional space-time, induced by a composite topological defect. The defect is constituted by a global monopole living on a…

High Energy Physics - Theory · Physics 2008-11-26 E. R. Bezerra de Mello , A. A. Saharian

We study the energy density and pressure of a relativistic thermal gas of massless fermions on four-dimensional Minkowski and anti-de Sitter space-times using relativistic kinetic theory. The corresponding quantum field theory quantities…

High Energy Physics - Theory · Physics 2018-01-17 Victor E. Ambrus , Elizabeth Winstanley

The main objective of this paper is to analyze the vacuum expectation value (VEV) of the energy-momentum tensor (EMT) associated with a charged scalar quantum field in a high-dimensional cosmic string spacetime admitting the presence of a…

High Energy Physics - Theory · Physics 2019-08-26 E. A. F. Bragança , H. F. Santana Mota , E. R. Bezerra de Mello

We evaluate the positive-frequency Wightman function, the vacuum expectation values (VEVs) of the field squared and the energy-momentum tensor for a massive scalar field with general curvature coupling for a cylindrical shell in background…

High Energy Physics - Theory · Physics 2014-12-23 A. A. Saharian , V. F. Manukyan

Complete set of modes and the Hadamard function are constructed for a scalar field inside and outside a sphere in (D+1)-dimensional de Sitter spacetime foliated by negative constant curvature spaces. We assume that the field obeys Robin…

High Energy Physics - Theory · Physics 2021-09-29 A. A. Saharian , T. A. Petrosyan

In the context of a string-inspired running vacuum model (RVM) of cosmology with anomalies and torsion-induced axion-like fields, we discuss quantum corrections to the corresponding energy density, in approximately de Sitter eras, during…

General Relativity and Quantum Cosmology · Physics 2023-07-28 Nick E. Mavromatos , Joan Solà Peracaula , Adrià Gómez-Valent

The relevant characteristic features, including energy per unit length and tension, of a cosmic string carrying massless fermionic currents in the framework of the Witten model in the neutral limit are derived through quantization of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Christophe Ringeval