scholarly journals Krein Space Quantization of Casimir Effect for a Spherical Shell

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
F. Payandeh
Keyword(s):  
Spherical Shell ◽  
Casimir Effect ◽  
Krein Space ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
De Sitter ◽  
Sitter Spacetime ◽  
Kreĭn Space ◽  
Krein Space Quantization

The Casimir stress on a spherical shell in de Sitter spacetime for a massless scalar field is calculated using Krein space quantization. In this method, the auxiliary negative frequency states have been utilized, the modes of which do not interact with the physical states and are not affected by the physical boundary conditions. These unphysical states just play the role of an automatic renormalization tool for the theory.

scholarly journals Casimir Effect in Domain Wall Formation

2003 ◽  
Vol 18 (23) ◽  
pp. 4285-4293 ◽  
Author(s):  
M. R. Setare
Keyword(s):  
Domain Wall ◽  
Boundary Conditions ◽  
Mixed Boundary ◽  
Casimir Effect ◽  
Mixed Boundary Conditions ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Parallel Plates ◽  
De Sitter ◽  
Casimir Forces

The Casimir forces on two parallel plates in conformally flat de Sitter background due to conformally coupled massless scalar field satisfying mixed boundary conditions on the plates is investigated. In the general case of mixed boundary conditions formulae are derived for the vacuum expectation values of the energy–momentum tensor and vacuum forces acting on boundaries. Different cosmological constants are assumed for the space between and outside of the plates to have general results applicable to the case of domain wall formations in the early universe.

scholarly journals Casimir effect in Krein space quantization

2006 ◽  
Vol 640 (1-2) ◽  
pp. 48-51 ◽  
Author(s):  
H. Khosravi ◽  
M. Naseri ◽  
S. Rouhani ◽  
M.V. Takook
Keyword(s):  
Casimir Effect ◽  
Krein Space ◽  
Kreĭn Space ◽  
Krein Space Quantization

scholarly journals Massless scalar field in de Sitter spacetime: unitary quantum time evolution

2013 ◽  
Vol 30 (7) ◽  
pp. 075015 ◽  
Author(s):  
Jerónimo Cortez ◽  
Daniel Martín-de Blas ◽  
Guillermo A Mena Marugán ◽  
José M Velhinho
Keyword(s):  
Scalar Field ◽  
Time Evolution ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Quantum Time ◽  
Sitter Spacetime

scholarly journals CASIMIR EFFECT FOR A SPHERICAL SHELL IN DE SITTER SPACE–TIME WITH SIGNATURE CHANGE

2008 ◽  
Vol 17 (12) ◽  
pp. 2261-2268
Author(s):  
M. R. SETARE ◽  
F. DARABI
Keyword(s):  
Spherical Shell ◽  
Casimir Effect ◽  
Scalar Fields ◽  
Dirichlet Boundary Conditions ◽  
Massless Scalar ◽  
Late Time ◽  
De Sitter ◽  
Signature Change ◽  
Sitter Background ◽  
Cosmological Constants

We calculate the Casimir stress on a spherical shell in a de Sitter background corresponding to different metric signatures and cosmological constants, for massless scalar fields that satisfy Dirichlet boundary conditions on the shell. We show that a contribution appears due to signature change, which leads to late-time expansion of the bubbles in this background.

scholarly journals SPECTRUM OF GRAVITATIONAL WAVES IN KREIN SPACE QUANTIZATION

2011 ◽  
Vol 26 (36) ◽  
pp. 2697-2702 ◽  
Author(s):  
M. MOHSENZADEH ◽  
A. SOJASI ◽  
E. YUSOFI
Keyword(s):  
Gravitational Waves ◽  
Krein Space ◽  
Slow Roll ◽  
Primordial Power Spectrum ◽  
Alternative Approach ◽  
Special Cases ◽  
Kreĭn Space ◽  
Field Quantization ◽  
Krein Space Quantization ◽  
Scalar Perturbations

The main goal of this paper is to derive the primordial power spectrum for the scalar perturbations generated as a result of quantum fluctuations during an inflationary period by an alternative approach of field quantization.1–3 Formulas are derived for the gravitational waves, special cases of which include power law inflation and inflation in the slow roll approximation, in Krein space quantization.

scholarly journals Quasi-normal modes and the area spectrum of a near extremal de Sitter black hole with conformally coupled scalar field

2015 ◽  
Vol 30 (11) ◽  
pp. 1550057 ◽  
Author(s):  
Sharmanthie Fernando
Keyword(s):  
Black Hole ◽  
Wave Equation ◽  
Scalar Field ◽  
Normal Modes ◽  
Type Equation ◽  
Area Spectrum ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
De Sitter ◽  
Quasi Normal Mode

In this paper, we have studied a black hole in de Sitter space which has a conformally coupled scalar field in the background. This black hole is also known as the MTZ black hole. We have obtained exact values for the quasi-normal mode (QNM) frequencies under massless scalar field perturbations. We have demonstrated that when the black hole is near-extremal, that the wave equation for the massless scalar field simplifies to a Schrödinger type equation with the well-known Pöschl–Teller potential. We have also used sixth-order WKB approximation to compute QNM frequencies to compare with exact values obtained via the Pöschl–Teller method for comparison. As an application, we have obtained the area spectrum using modified Hods approach and show that it is equally spaced.

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