scholarly journals Induced Cosmological Constant in Braneworlds with Compact Dimensions

2018 ◽  
pp. 315-326
Author(s):  
A. A. Saharian ◽  
H. G. Sargsyan
Keyword(s):  
Magnetic Flux ◽  
Cosmological Constant ◽  
Function Technique ◽  
Vacuum Energy Density ◽  
De Sitter ◽  
Charged Scalar ◽  
Sitter Spacetime ◽  
Compact Dimension ◽  
Spatial Dimensions ◽  
Aharonov Bohm

We investigate the cosmological constant induced by quantum fluctuations of a bulk charged scalar field on a brane in background of locally anti-de Sitter spacetime with toroidally compact spatial dimensions. Along compact dimension quasiperiodicity conditions are imposed with general phases and, in addition, the presence of a constant gauge field is assumed. The latter gives rise to Aharonov-Bohm type effect on the characteristics of the scalar vacuum. The renormalization of the vacuum energy density on the brane is done by making use of the generalized zeta function technique. The behavior of the cosmological constant is studied as a function of the location of the brane, of the length of the compact dimensions and of the magnetic flux enclosed by the compact dimension. In particular, it is shown that the cosmological constant is a periodic function of the magnetic flux with the period equal to the flux quantum.

scholarly journals QUANTUM EFFECTS IN HIGHER-DIMENSIONAL COSMOLOGICAL MODELS

2012 ◽  
Vol 18 ◽  
pp. 164-173 ◽  
Author(s):  
ARAM A. SAHARIAN
Keyword(s):  
Vacuum Energy ◽  
Vacuum Expectation ◽  
Vacuum Energy Density ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Expectation Values ◽  
Sitter Spacetime ◽  
Higher Dimensional ◽  
Spatial Dimensions ◽  
Robin Boundary

Vacuum energy density and stresses are investigated for a scalar field in de Sitter spacetime with an arbitrary number of toroidally compactified spatial dimensions and in anti-de Sitter spacetime with two parallel branes. On the branes the field obeys the Robin boundary conditions. The behavior of the vacuum expectation values is discussed in various asymptotic regions of the parameters. Applications are given to Randall-Sundrum type braneworlds.

scholarly journals CASIMIR EFFECT IN TOROIDALLY COMPACTIFIED DE SITTER SPACETIME

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1813-1820 ◽  
Author(s):  
A. A. SAHARIAN
Keyword(s):  
Casimir Effect ◽  
Coupling Parameter ◽  
Vacuum Expectation ◽  
Vacuum Energy Density ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Expectation Values ◽  
Sitter Spacetime ◽  
Spatial Dimensions ◽  
Late Stages

Vacuum energy density and stresses are investigated for a scalar field with general curvature coupling parameter in (D + 1)-dimensional de Sitter spacetime with an arbitrary number of toroidally compactified spatial dimensions. The corresponding expectation values are presented in the form of the sum of the vacuum expectation values in uncompactified dS spacetime and the part induced by the non-trivial topology. In the early stages of the cosmological evolution the topological parts dominate. In this limit the behavior of the Casimir densities does not depend on the curvature coupling parameter and coincides with that for a conformally coupled massless field. At late stages of the cosmological expansion the expectation values are dominated by the part corresponding to uncompactified dS spacetime. The vanishing of the topological parts is monotonic or oscillatory in dependence of the mass and the curvature coupling parameter of the field.

scholarly journals Relationship between Bondi–Sachs quantities and source of gravitational radiation in asymptotically de Sitter spacetime

2018 ◽  
Vol 27 (04) ◽  
pp. 1850046 ◽  
Author(s):  
Xiaokai He ◽  
Jiliang Jing ◽  
Zhoujian Cao
Keyword(s):  
Cosmological Constant ◽  
Gravitational Wave ◽  
Gravitational Radiation ◽  
The Other ◽  
Perturbation Approach ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Positive Cosmological Constant ◽  
Sitter Spacetime ◽  
Explicit Expressions

Gravitational radiation plays an important role in astrophysics. Based on the fact that our universe is expanding, the gravitational radiation when a positive cosmological constant is presented has been studied along with two different ways recently, one is the Bondi–Sachs (BS) framework in which the result is shown by BS quantities in the asymptotic null structure, the other is the perturbation approach in which the result is presented by the quadrupoles of source. Therefore, it is worth to interpret the quantities in asymptotic null structure in terms of the information of the source. In this paper, we investigate this problem and find the explicit expressions of BS quantities in terms of the quadrupoles of source in asymptotically de Sitter spacetime. We also estimate how far away the source is, the cosmological constant may affect the detection of the gravitational wave.

scholarly journals ON DETERMINATION OF THE GEOMETRIC COSMOLOGICAL CONSTANT FROM THE OPERA EXPERIMENT OF SUPERLUMINAL NEUTRINOS

2012 ◽  
Vol 27 (11) ◽  
pp. 1250041 ◽  
Author(s):  
MU-LIN YAN ◽  
SEN HU ◽  
WEI HUANG ◽  
NENG-CHAO XIAO
Keyword(s):  
Dark Energy ◽  
Cosmological Constant ◽  
Fundamental Constant ◽  
Zero Point ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Point Energy ◽  
Sitter Spacetime ◽  
Effective Cosmological Constant

The recent OPERA experiment of superluminal neutrinos has deep consequences in cosmology. In cosmology a fundamental constant is the cosmological constant. From observations one can estimate the effective cosmological constant Λ eff which is the sum of the quantum zero point energy Λ dark energy and the geometric cosmological constant Λ. The OPERA experiment can be applied to determine the geometric cosmological constant Λ. It is the first study to distinguish the contributions of Λ and Λ dark energy from each other by experiment. The determination is based on an explanation of the OPERA experiment in the framework of Special Relativity with de Sitter spacetime symmetry.

scholarly journals Schwinger pair production and the extended uncertainty principle: can heuristic derivations be trusted?

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Yen Chin Ong
Keyword(s):  
Cosmological Constant ◽  
Pair Production ◽  
Uncertainty Principle ◽  
Correction Term ◽  
Correct Result ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime ◽  
Extended Uncertainty ◽  
Background Curvature

Abstract The rate of Schwinger pair production due to an external electric field can be derived heuristically from the uncertainty principle. In the presence of a cosmological constant, it has been argued in the literature that the uncertainty principle receives a correction due to the background curvature, which is known as the “extended uncertainty principle” (EUP). We show that EUP does indeed lead to the correct result for Schwinger pair production rate in anti-de Sitter spacetime (the case for de Sitter spacetime is similar), provided that the EUP correction term is negative (positive for the de Sitter case). We compare the results with previous works in the EUP literature, which are not all consistent. Our result further highlights an important issue in the literature of generalizations of the uncertainty principle: how much can heuristic derivations be trusted?

scholarly journals Dark energy and quantum gravity

2019 ◽  
Vol 28 (14) ◽  
pp. 1944018 ◽  
Author(s):  
Per Berglund ◽  
Tristan Hübsch ◽  
Djordje Minić
Keyword(s):  
Dark Energy ◽  
String Theory ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Particle Physics ◽  
Dual Space ◽  
Planck Scale ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime

Realizing dark energy and the observed de Sitter spacetime in quantum gravity has proven to be obstructed in almost every usual approach. We argue that additional degrees of freedom of the left- and right-movers in string theory and a resulting doubled, noncommutatively generalized geometric formulation thereof can lead to an effective model of dark energy consistent with de Sitter spacetime. In this approach, the curvature of the canonically conjugate dual space provides for the dark energy inducing a positive cosmological constant in the observed spacetime, whereas the size of the above dual space is the gravitational constant in the same observed de Sitter spacetime. As a hallmark relation owing to a unique feature of string theory which relates short distances to long distances, the cosmological constant scale, the Planck scale and the effective TeV-sized particle physics scale must satisfy a see-saw-like formula — precisely the generic prediction of certain stringy cosmic brane type models.

scholarly journals AMPLITUDE OF COULOMB SCATTERING FOR CHARGED SCALAR FIELD IN DE SITTER SPACETIME

2010 ◽  
Vol 25 (20) ◽  
pp. 1679-1687 ◽  
Author(s):  
COSMIN CRUCEAN
Keyword(s):  
Scalar Field ◽  
Gordon Equation ◽  
Coulomb Scattering ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Scattering Process ◽  
Charged Scalar ◽  
Sitter Spacetime ◽  
Klein Gordon ◽  
Charged Scalar Field

The scattering of a charged scalar field on Coulomb potential is studied using solutions of the Klein–Gordon equation which have a definite momentum. One obtains that the modulus of momentum is not conserved in the scattering process on de Sitter space.

scholarly journals EXTENDED UNCERTAINTY PRINCIPLE AND THE GEOMETRY OF (ANTI)-DE SITTER SPACE

2010 ◽  
Vol 25 (20) ◽  
pp. 1697-1703 ◽  
Author(s):  
S. MIGNEMI
Keyword(s):  
Cosmological Constant ◽  
Uncertainty Principle ◽  
Generalized Uncertainty Principle ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Heisenberg Uncertainty Principle ◽  
Sitter Spacetime ◽  
Heisenberg Uncertainty ◽  
Sitter Background ◽  
Extended Uncertainty

It has been proposed that on (anti)-de Sitter background, the Heisenberg uncertainty principle should be modified by the introduction of a term proportional to the cosmological constant. We show that this modification of the uncertainty principle can be derived straightforwardly from the geometric properties of (anti)-de Sitter spacetime. We also discuss the connection between the so-called extended generalized uncertainty principle and triply special relativity.

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