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Singular configuration of an external static magnetic field in the form of a string polarizes vacuum in the secondly quantized theory on a plane which is orthogonal to the string axis. We consider the most general boundary conditions at the…

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

The bosonic membrane in a partial gauge, where one space dimension is eliminated, is formulated as a perturbation theory around an exact free string-like solution. This perturbative regime corresponds to a situation where one of the…

High Energy Physics - Theory · Physics 2009-11-10 Jonas Bjornsson , Stephen Hwang

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

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

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

We evaluate the Wightman function, the mean field squared and the vacuum expectation value (VEV) of the energy-momentum tensor for a scalar field with Robin boundary condition on a spherical shell in the background of a constant negative…

High Energy Physics - Theory · Physics 2014-09-29 S. Bellucci , A. A. Saharian , N. A. Saharyan

The virial and the Hellmann--Feynman theorems for massless Dirac electrons in a solid are derived and analyzed using generalized continuity equations and scaling transformations. Boundary conditions imposed on the wave function in a finite…

Mesoscale and Nanoscale Physics · Physics 2019-11-18 Alexey A. Sokolik , Andrey D. Zabolotskiy , Yurii E. Lozovik

In this paper we consider a charged massless scalar quantum field operator in the spacetime of an idealized cosmic string, i.e., an infinitely long, straight and static cosmic string, which presents a magnetic field confined in a…

High Energy Physics - Theory · Physics 2017-08-23 J. Spinelly , E. R. Bezerra de Mello

In this paper we analyse the vacuum polarization effect associated with the charged massless scalar field, in the presence of magnetic flux at finite temperature, in the cosmic string background. We consider a spacetime of an idealized…

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

The emergence of the concept of a causal fermion system is revisited and further investigated for the vacuum Dirac equation in Minkowski space. After a brief recap of the Dirac equation and its solution space, in order to allow for the…

Mathematical Physics · Physics 2020-12-15 Marco Oppio

We analyze the basic cosmological effects of a population of timelike boundaries -- a form of nontrivial spacetime topology -- containing a boundary layer of quantum stress energy. This accumulation of vacuum fluctuations of quantum fields…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-26 Oliver H. E. Philcox , Eva Silverstein , Gonzalo Torroba

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

We investigate the vacuum-induced current density for a charged scalar field in a $(D+1)$-dimensional cosmic dispiration spacetime threaded by a magnetic flux. This background combines a cosmic string and a screw dislocation, yielding a…

High Energy Physics - Theory · Physics 2026-04-10 Herondy Mota

We analyze the vacuum fluctuations and the stress-energy tensor of a scalar field of mass $M$ in a conical spacetime, where the topological singularity at the apex requires boundary conditions for the field equation. The necessity of…

High Energy Physics - Theory · Physics 2025-12-05 João Paulo M. Pitelli , Ricardo A. Mosna , Victor Hugo M. Ramos , João C. A. Barata

In a recent article, a simple `spherical bubble' toy model for a spatially varying vacuum energy density was introduced, and type Ia supernovae data was used to constrain it. Here we generalize the model to allow for the fact that we may…

Astrophysics · Physics 2009-11-06 P. P. Avelino , A. Canavezes , J. P. M. de Carvalho , C. J. A. P. Martins

The possibility of the cosmic string creation by the vacuum fluctuations of quantum fields in the self-consistent semiclassical theory of gravity is discussed. We use the approximate method for obtaining vacuum expectation value of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Arkadii Popov

Fermi condensation is usually a phenomena of strongly correlated system. In this letter, we point out a novel mechanism for condensation of Dirac fermions due to Weyl anomaly. The condensation has its physical origin in the nontrivial…

High Energy Physics - Theory · Physics 2020-08-28 Chong-Sun Chu , Rong-Xin Miao

We present a detailed Hamiltonian treatment of an inhomogeneous fermionic perturbation propagating on a closed FLRW spacetime quantized via LQC. Expanding the fermion in spinor harmonics on spatial 3-sphere and truncating at quadratic…

General Relativity and Quantum Cosmology · Physics 2025-10-02 Yaser Tavakoli , Ahad K. Ardabili , Sara Mosaddegh

In a previous paper (hep-th/0509067) using matrix model, we showed that closed string tachyons can resolve spacelike singularity in one particular class of Misner space (with anti-periodic boundary conditions for fermions around the spatial…

High Energy Physics - Theory · Physics 2008-11-26 Jian-Huang She

The Casimir forces on two parallel plates in conformally flat domain wall background due to conformally coupled massless scalar field satisfying mixed boundary conditions on the plates is investigated. In the general case of mixed boundary…

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