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Related papers: Quantum effects in higher-dimensional cosmological…

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Energy momentum tensor of a conformally coupled quantum scalar field in five dimensional warped cosmological spacetimes is studied. We look at situations where the four dimensional part represents a cosmological thick brane and the scale of…

General Relativity and Quantum Cosmology · Physics 2019-03-27 Suman Ghosh

Vacuum plane symmetric solutions within $\alpha R^n$ modified gravity are obtained. The solutions can be regarded as describing thick branes with codimension 1 in a higher-dimensional spacetime. The dependence of the solutions on the values…

General Relativity and Quantum Cosmology · Physics 2020-01-01 V. Dzhunushaliev , V. Folomeev , A. Serikbolova

In this Letter we show that the vacuum polarization of quantum fields in an anti-de Sitter space naturally gives rise to a small but nonzero cosmological constant in a brane world living in it. To explain the extremely small ratio of mass…

High Energy Physics - Theory · Physics 2010-11-05 Li-Xin Li

The de Sitter thermodynamics of cosmological models with a modified Friedmann equation is considered, with particular reference to high-energy Randall-Sundrum and Gauss-Bonnet braneworlds. The Friedmann equation can be regarded as the first…

High Energy Physics - Theory · Physics 2009-11-11 Gianluca Calcagni

We evaluate the Hadamard function and the vacuum expectation value (VEV) of the current density for a charged scalar field in the region between two co-dimension one branes on the background of locally AdS spacetime with an arbitrary number…

High Energy Physics - Theory · Physics 2016-04-13 S. Bellucci , A. A. Saharian , V. Vardanyan

We consider cosmological models where the universe, governed by Einstein's equations, is a piece of a five dimensional double-sided anti-de Sitter spacetime (that is, a "$Z_2$-symmetric bulk") with matter confined to its four dimensional…

High Energy Physics - Theory · Physics 2009-10-31 Nathalie Deruelle , Tomas Dolezel , Joseph Katz

In this paper we show, through the study of concrete examples, that, depending on the cosmic dynamics of the energy density of matter degrees of freedom living in the brane, Randall-Sundrum (RS) brane effects can be important not only at…

General Relativity and Quantum Cosmology · Physics 2011-08-19 Ricardo García-Salcedo , Tame Gonzalez , Claudia Moreno , Israel Quiros

In the generalized Randall-Sundrum warped brane-world model the cosmological constant induced on the visible brane can be positive or negative. In this paper we investigate profiles of vacuum expectation value of the bulk scalar field under…

General Relativity and Quantum Cosmology · Physics 2015-10-06 A. Tofighi , M. Moazzen , A. Farokhtabar

Fermionic condensate and the vacuum expectation values of the energy-momentum tensor are investigated for twisted and untwisted massive spinor fields in higher-dimensional de Sitter spacetime with toroidally compactified spatial dimensions.…

High Energy Physics - Theory · Physics 2008-12-25 E. R. Bezerra de Mello , A. A. Saharian

A generalized version of the Randall-Sundrum model-2 with different cosmological constants on each side of a brane has been discussed. A possibility of replacing the singular brane by a configuration of a scalar field has been also…

High Energy Physics - Theory · Physics 2015-06-18 Aqeel Ahmed , Lukasz Dulny , Bohdan Grzadkowski

Brane dark energy cosmologies, leading to various possible evolutions of our universe, are investigated. The discussion shows that while all these models can be made arbitrarily close to the standard $\Lambda$CDM cosmology at present, their…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Artyom V. Astashenok , Emilio Elizalde , Sergei D. Odintsov , Artyom V. Yurov

The vacuum expectation value of the surface energy-momentum tensor is evaluated for a scalar field obeying Robin boundary condition on a spherical brane in (D+1)-dimensional spacetime $Ri\times S^{D-1}$, where $Ri$ is a two-dimensional…

High Energy Physics - Theory · Physics 2008-11-26 A. A. Saharian , M. R. Setare

Since the Randall-Sundrum 1999 papers, braneworlds have been a favourite playground to test string inspired cosmological models. The subject has developped into two main directions : elaborating more complex models in order to strenghten…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Nathalie Deruelle

Positive frequency Wightman function, vacuum expectation values of the field square and the energy-momentum tensor induced by a Z_{2}-symmetric brane with finite thickness located on (D+1)- dimensional AdS background are evaluated for a…

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

We investigate the vacuum expectation value of the surface energy-momentum tensor for a massive scalar field with general curvature coupling parameter obeying the Robin boundary conditions on two codimension one parallel branes in a…

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

We investigate the vacuum expectation value of the surface energy-momentum tensor (SEMT) for a scalar field with general curvature coupling in the geometry of two branes orthogonal to the boundary of anti-de Sitter (AdS) spacetime. For…

High Energy Physics - Theory · Physics 2024-01-23 A. A. Saharian

We discuss the dynamics of a spherically symmetric dark radiation vaccum in the Randall-Sundrum brane world scenario. Under certain natural assumptions we show that the Einstein equations on the brane form a closed system. For a de Sitter…

High Energy Physics - Theory · Physics 2017-08-23 Rui Neves , Cenalo Vaz

The vacuum expectation value of the stress-energy tensor $\left\langle 0\left| T_{\mu\nu} \right|0\right\rangle$ is calculated in several multiply connected flat spacetimes for a massive scalar field with arbitrary curvature coupling. We…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Tsunefumi Tanaka , William A. Hiscock

We consider the Randall-Sundrum braneworld theory with a single extra dimension of infinite extent to investigate generalized $f(R)$ braneworld models in the presence of several real scalar fields. In particular, we solve the modified…

High Energy Physics - Theory · Physics 2015-06-16 D. Bazeia , R. Menezes , A. Yu. Petrov , A. J. da Silva

Quantum inequality restrictions on the stress-energy tensor for negative energy are developed for three and four-dimensional static spacetimes. We derive a general inequality in terms of a sum of mode functions which constrains the…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Michael J. Pfenning , L. H. Ford