Related papers: Vacuum polarization induced by a cosmic string and…
We investigate a string-inspired scenario associated with a rolling massive scalar field on D-branes and discuss its cosmological implications. In particular, we discuss cosmological evolution of the massive scalar field on the ant-D3 brane…
We derive the full projected Einstein-Brans-Dicke gravitational equations associated with a n-dimensional brane embedded in a (n+1)-dimensional bulk. By making use of general conditions, as the positivity of the Brans-Dicke parameter and…
We propose an effective model for an exponentially expanding universe in the brane-world scenario. The setup consists of a 5D black hole and a brane close to the black hole horizon. In case the brane acquires a specific configuration, which…
We investigate the effects of a $(D+1)$-dimensional global monopole core on the behavior of a quantum massive scalar field with general curvature coupling parameter. In the general case of the spherically symmetric static core, formulae are…
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…
We investigate the behaviour of classical and quantum fields in the conical space-time associated with a point mass in 2+1 dimensions. We show that the presence of conical boundary conditions alters the electrostatic field of a point charge…
We investigate the vacuum expectation value of bosonic current induced by a magnetic flux in a $(2+1)-$dimensional conical spacetime in the presence of a circular boundary, in a Ho{\v{r}}ava-Lifshitz Lorentz violation symmetry scenario. We…
Vacuum expectation values of the surface energy-momentum tensor is investigated for a massless scalar field obeying mixed boundary condition on a brane in de Sitter bulk. To generate the corresponding vacuum surface densities we use the…
In this paper we present a complete and detailed analysis of the calculation of both the Wightman function and the vacuum expectation value of the energy-momentum tensor that arise from quantum vacuum fluctuations of massive and massless…
The string and brane tensions do not have to be put in by hand, they can be dynamically generated, as in the case when we formulate string and brane theories in the modified measure formalism. Then string and brane tensions appears, but as…
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…
A singular configuration of an external static vector field in the form of a magnetic string polarizes the vacuum of a second-quantized theory on the plane orthogonal to the string axis. The most general boundary conditions at the punctured…
We study brane-world models with variable brane tension and compute corrections to the horizon of a black string along the extra dimension. The four-dimensional geometry of the black string on the brane is obtained by means of the minimal…
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…
In brane world models, combining the extra dimensional field modes with the standard four dimensional ones yields interesting physical consequences that have been proved from high energy physics to cosmology. Even some low energy phenomena…
We investigate the cosmological evolution of gravitational waves in Friedman-Robertson-Walker brane world models embedded in a five dimensional anti de-Sitter spacetime. To predict the spectrum of stochastic gravitational background at…
Among the multiple 5D thick braneworld models that have been proposed in the last years, in order to address several open problems in modern physics, there is a specific one involving a tachyonic bulk scalar field. Delving into this…
In this paper, vacuum expectation value (VEV) of the energy-momentum tensor for a conformally coupled scalar field in de Sitter space-time is investigated through the Krein-Gupta-Bleuler construction. This construction has already been…
In a previous work [S. Rahbardehghan et al. in Phys. Lett. B 750, 627 (2015)], we considered a simple brane-world model; a single $4$-dimensional brane embedded in a $5$-dimensional de Sitter (dS) space-time. Then, by including a…
The vacuum expectation value of the square of the field fluctuations of a scalar field on a background consisting of {\it two} de Sitter branes embedded in an anti-de Sitter bulk are considered. We apply a dimensional reduction to obtain an…