English
Related papers

Related papers: Cosmic string and brane induced effects on the fer…

200 papers

Vacuum expectation values (VEVs) of the current densities for charged scalar and Dirac spinor fields are investigated in (D+1)-dimensional de Sitter (dS) spacetime with toroidally compactified spatial dimensions. Along compact dimensions we…

High Energy Physics - Theory · Physics 2013-08-02 S. Bellucci , A. A. Saharian , H. A. Nersisyan

In this paper we investigate the vacuum expectation values of the field squared and the energy-momentum tensor associated to a charged massive scalar quantum field in a $(1+D)$-dimensional de Sitter spacetime induced by a plate (flat…

High Energy Physics - Theory · Physics 2024-01-17 W. Oliveira dos Santos , E. R. Bezerra de Mello

In this paper, we study the time-dependent dynamics of an end-of-the-world (EOW) brane in AdS with a scalar field localized on the brane. We mainly studied several aspects of holography and cosmology. Standard requirements in the…

High Energy Physics - Theory · Physics 2025-01-22 Kosei Fujiki , Hiroki Kanda , Michitaka Kohara , Tadashi Takayanagi

In this paper, we analyze the vacuum azimuthal fermionic current induced by a magnetic field confined in a cylindrical tube of finite radius $a$, in the cosmic string spacetime. Three distinct configurations for the magnetic field are taken…

High Energy Physics - Theory · Physics 2018-03-28 M. S. Maior de Sousa , R. F. Ribeiro , E. R. Bezerra de Mello

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 toy model we discuss the phenomenon of colliding five-branes, with two of the extra space dimensions compactified on tori. In one of the branes (hidden world) the torus is magnetised. Assuming opposite-tension branes, we…

High Energy Physics - Theory · Physics 2014-11-18 Elias Gravanis , Nick E. Mavromatos

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 investigate the finite temperature expectation values of the charge and current densities for a massive fermionic field with nonzero chemical potential, $\mu$, in the geometry of a straight cosmic string with a magnetic flux running…

High Energy Physics - Theory · Physics 2015-06-12 A. Mohammadi , E. R. Bezerra de Mello , A. A. Saharian

We describe cosmic F--term strings with exponentially small tension which are D3 branes wrapped on deformed $A_3$ singularities. We show that brane instanton effects which can be calculated after a geometric transition give rise to an…

High Energy Physics - Theory · Physics 2009-08-18 Edi Halyo

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

In this paper, we consider a charged massive fermionic quantum field in the space-time of an idealized cosmic string, in the presence of a magnetic field confined in a cylindrical tube of finite radius. Three distinct configurations for the…

High Energy Physics - Theory · Physics 2016-03-02 M. S. Maior de Sousa , R. F. Ribeiro , E. R. Bezerra de Mello

For a massive scalar field with a general curvature coupling parameter, we investigate the finite temperature contributions to the Hadamard function and to the charge and current densities in the geometry of a magnetic flux carrying…

High Energy Physics - Theory · Physics 2022-12-28 E. R. Bezerra de Mello , W. Oliveira dos Santos , A. A. Saharian

We investigate the properties of the fermionic Fulling-Rindler vacuum for a massive Dirac field in a general number of spatial dimensions. As important local characteristics, the fermionic condensate and the expectation value of the…

High Energy Physics - Theory · Physics 2023-11-17 S. Bellucci , V. Kh. Kotanjyan , A. A. Saharian

We investigate the fermionic condensate and the vacuum expectation values of the energy-momentum tensor for a massive spinor field in de Sitter spacetime with spatial topology $\mathrm{R}^{p}\times (\mathrm{S}^{1})^{q}$. Both cases of…

High Energy Physics - Theory · Physics 2008-11-26 A. A. Saharian

In this paper, we investigate 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…

High Energy Physics - Theory · Physics 2022-05-03 E. A. F. Bragança , E. R. Bezerra de Mello , A. Mohammadi

If we live on the weak brane with zero effective cosmological constant in a warped 5D bulk spacetime, gravitational waves and brane fluctuations can be generated by a part of the 5D Weyl tensor and carries information of the gravitational…

General Relativity and Quantum Cosmology · Physics 2016-04-20 Reinoud Jan Slagter , Supriya Pan

Compactifications of type IIB string theory on AdS5 x X5, where X5 is an Einstein space, can have one-fourth or half maximal supersymmetry for certain choices of X5. Some of these theories admit exotic domain walls arising from 5-branes…

High Energy Physics - Theory · Physics 2009-10-31 Keshav Dasgupta , Sunil Mukhi

Two-point functions, the mean field squared and the vacuum expectation value (VEV) of the energy-momentum tensor are investigated for the electromagnetic field in the geometry of parallel plates on background of $(D+1)$% -dimensional dS…

High Energy Physics - Theory · Physics 2015-05-28 A. S. Kotanjyan , A. A. Saharian , H. A. Nersisyan

Recent developments in string theory have led to 5-dimensional warped spacetime models in which standard-model fields are confined to a 3-brane (the observed universe), while gravity can propagate in the fifth dimension. Gravity is…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Roy Maartens

The supporting worldsheet of a string, membrane, or other higher dimensional brane, is analysed in terms of its first, second, and third fundamental tensors, and its inner and outer curvature tensors. The dynamical equations governing the…

High Energy Physics - Theory · Physics 2007-05-23 Brandon Carter
‹ Prev 1 3 4 5 6 7 10 Next ›