scholarly journals Casimir energy corrections by light-cone fluctuations

2014 ◽  
Vol 29 (05) ◽  
pp. 1450024 ◽  
Author(s):  
E. Arias ◽  
J. G. Dueñas ◽  
N. F. Svaiter ◽  
C. H. G. Bessa ◽  
G. Menezes
Keyword(s):  
Light Cone ◽  
Zero Point ◽  
Casimir Energy ◽  
Vacuum Energy Density ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Parallel Plates ◽  
Point Energy ◽  
Klein Gordon ◽  
Free Case

We study the effects of light-cone fluctuations on the renormalized zero-point energy associated with a free massless scalar field in the presence of boundaries. In order to simulate light-cone fluctuations, we introduce a space–time dependent random coefficient in the Klein–Gordon operator. We assume that the field is defined in a domain with one confined direction. For simplicity, we choose the symmetric case of two parallel plates separated by a distance a. The correction to the renormalized vacuum energy density between the plates goes as 1/a8 instead of the usual 1/a4 dependence for the free case. In turn, we also show that light-cone fluctuations break down the vacuum pressure homogeneity between the plates.

scholarly journals Casimir effect in space-times of rotating wormholes

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
C. R Muniz ◽  
V. B. Bezerra ◽  
J. M. Toledo
Keyword(s):  
Black Hole ◽  
Energy Density ◽  
Casimir Effect ◽  
Kerr Black Hole ◽  
Casimir Energy ◽  
Vacuum Energy Density ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Thermodynamic Quantities ◽  
Parallel Plates

AbstractWe investigate the Casimir effect between parallel plates placed along a circular trajectory around the rotating Damour–Solodkhin (D–S) and Teo wormholes. This is made through the calculation of the renormalized quantum vacuum energy density of a massless scalar field obeying the Dirichlet boundary conditions, initially at zero temperature. We use the zero tidal approximation inside the cavity. Then, we compare our results with those ones previously obtained in the literature with respect to the Kerr black hole. We also compare the computed Casimir energy density in a static D–S wormhole spacetime with that one recently found for a static Ellis wormhole. In what follows, we investigate the effect around the rotating Teo wormhole by calculating the Casimir energy density between the plates, and compare it with the same quantities obtained previously. Finally, we investigate the phenomenon at finite temperature, obtaining some Casimir thermodynamic quantities in the rotating D–S wormhole spacetime, comparing them with the ones valid in the Kerr black hole spacetime. With this, the ways as gravito-inertial and frame dragging effects influence the vacuum quantum fluctuations inside the Casimir apparatus allows to distinct among the different types of rotating wormholes and black holes.

VACUUM ENERGY IN SPHERICAL DOMAINS: WKB AND UNIFORM ASYMPTOTIC EXPANSIONS

1996 ◽  
Vol 11 (22) ◽  
pp. 4129-4146 ◽  
Author(s):  
AUGUST ROMEO
Keyword(s):  
Zeta Function ◽  
Asymptotic Expansions ◽  
Zero Point ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Point Energy ◽  
Dimensional Dependence ◽  
Spherical Domains ◽  
Spectral Zeta Function ◽  
Uniform Asymptotic Expansions

We evaluate the finite part of the regularized zero-point energy for a massless scalar field confined in the interior of a D-dimensional spherical region. While some insight is offered into the dimensional dependence of the WKB approximations by examining the residues of the spectral-zeta-function poles, a mode-sum technique based on an integral representation of the Bessel spectral zeta function is applied with the help of uniform asymptotic expansions (u.a.e.’s).

scholarly journals SCALAR CASIMIR EFFECT BETWEEN TWO CONCENTRIC SPHERES

2012 ◽  
Vol 27 (16) ◽  
pp. 1250082 ◽  
Author(s):  
MUSTAFA ÖZCAN
Keyword(s):  
Scalar Field ◽  
Casimir Effect ◽  
Casimir Energy ◽  
Outer Radius ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Parallel Plates ◽  
New Approach ◽  
Concentric Spheres ◽  
Spherical Boundary

The Casimir effect giving rise to an attractive force between the closely spaced two concentric spheres that confine the massless scalar field is calculated by using a direct mode summation with contour integration in the complex plane of eigenfrequencies. We developed a new approach appropriate for the calculation of the Casimir energy for spherical boundary conditions. The Casimir energy for a massless scalar field between the closely spaced two concentric spheres coincides with the Casimir energy of the parallel plates for a massless scalar field in the limit when the dimensionless parameter η, ([Formula: see text] where a(b) is inner (outer) radius of sphere), goes to zero. The efficiency of new approach is demonstrated by calculation of the Casimir energy for a massless scalar field between the closely spaced two concentric half spheres.

scholarly journals Casimir effect in an axially symmetric spacetime with unparticles

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
V. B. Bezerra ◽  
C. R. Muniz ◽  
H. S. Vieira
Keyword(s):  
Energy Density ◽  
Characteristic Length ◽  
Casimir Effect ◽  
Casimir Energy ◽  
Einstein Equations ◽  
Kerr Solution ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Parallel Plates ◽  
Axially Symmetric

Abstract We investigate the Casimir effect of the massless scalar field in a cavity formed by ideal parallel plates in the spacetime generated by a rotating axially symmetric distribution of vector or scalar (tensor) unparticles, around which the plates orbit. The presence of the unparticles is incorporated to the background by means of a correction to the Kerr solution of the Einstein equations, in which the characteristic length and the scale dimension associated to the unparticle theory are taken into account. We show that the Casimir energy density depends also on these parameters. The analysis of the “ungravity” limit for the Casimir energy density, in which the characteristic length is very large in comparison to the horizon radius, is made, too. At zero temperature, we show that such a limit implies the instability of the system, since the Casimir energy density becomes an imaginary quantity. The general result is compared to the current terrestrial experiments of the Casimir effect. Thermal corrections also are investigated and the ungravity limit again examined, with the aforementioned instability disappearing at high temperatures.

scholarly journals Casimir effect in the Kerr spacetime with quintessence

2016 ◽  
Vol 32 (01) ◽  
pp. 1750005 ◽  
Author(s):  
V. B. Bezerra ◽  
M. S. Cunha ◽  
L. F. F. Freitas ◽  
C. R. Muniz ◽  
M. O. Tahim
Keyword(s):  
Casimir Effect ◽  
Polar Angle ◽  
State Parameter ◽  
Spherical Body ◽  
Casimir Energy ◽  
Radial Coordinate ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Parallel Plates ◽  
Kerr Spacetime

We calculate the Casimir energy of a massless scalar field in a cavity formed by nearby parallel plates orbiting a rotating spherical body surrounded by quintessence, investigating the influence of the gravitational field on that energy, at zero temperature. This influence includes the effects due to the spacetime dragging caused by the source rotation as well as those ones due to the quintessence. We show that the energy depends on all the involved parameters, as source mass, angular momentum and quintessence state parameter, for any radial coordinate and polar angle. We show that at the north pole the Casimir energy is not influenced by the quintessential matter. At the equatorial plane, when the quintessence is canceled, the result obtained in the literature is recovered. Finally, constraints in the quintessence parameters are obtained from the uncertainty in the current measurements of Casimir effect.

scholarly journals Casimir effect in a Schwarzschild-like wormhole spacetime

2021 ◽  
pp. 2150032
Author(s):  
A. C. L. Santos ◽  
C. R. Muniz ◽  
L. T. Oliveira
Keyword(s):  
Scalar Field ◽  
Casimir Energy ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Inertial Effects ◽  
Quantum Vacuum ◽  
Parallel Plates ◽  
Vacuum Fluctuations ◽  
Material Particle ◽  
Isotropic Coordinates

In this paper, we investigate the role of gravito-inertial effects on the Casimir energy of a massless scalar field confined between two parallel plates orbiting a static and zero tidal Schwarzschild-like wormhole, at zero temperature. Firstly, we obtain the metric in isotropic coordinates, finding the allowed angular velocities and the circular orbit radii for a material particle as well as for the photon. Following this, we compute the changes induced by both gravity and rotation of the plates in the energy density of the quantum vacuum fluctuations associated to the scalar field, in the zero tidal approximation inside the cavity. Finally, the Casimir energy obtained for some these wormholes are graphically compared between themselves and also with those ones related to an Ellis wormhole as well as to a Schwarzschild black hole. With this, the gravito-inertial effects on the quantum vacuum fluctuations analyzed in this work allow to recognize and identify both the geometry and topology of the spacetime associated to each one of these objects.

scholarly journals CASIMIR ENERGY OF MASSLESS FERMIONS IN THE SLAB-BAG

1999 ◽  
Vol 14 (34) ◽  
pp. 2353-2361 ◽  
Author(s):  
R. D. M. DE PAOLA ◽  
R. B. RODRIGUES ◽  
N. F. SVAITER
Keyword(s):  
Dimensional Space ◽  
Zero Point ◽  
Casimir Energy ◽  
Space Time ◽  
Fermion Field ◽  
Parallel Plates ◽  
Zero Point Energy ◽  
Massless Fermion ◽  
Point Energy ◽  
Dimensional Space Time

The zero-point energy of a massless fermion field in the interior of two parallel plates in a D-dimensional space–time at zero temperature is calculated. In order to regularize the model, a mix between dimensional and zeta-function regularization procedure is used and it is found that the regularized zero-point energy density is finite for any number of space–time dimensions. We present a general expression for the Casimir energy of the fermionic field in such a situation.

scholarly journals ZERO-POINT ENERGY OF MASSLESS SCALAR FIELDS IN THE PRESENCE OF SOFT AND SEMIHARD BOUNDARIES IN D DIMENSIONS

1999 ◽  
Vol 14 (13) ◽  
pp. 2077-2089 ◽  
Author(s):  
F. CARUSO ◽  
R. DE PAOLA ◽  
N. F. SVAITER
Keyword(s):  
Scalar Field ◽  
Energy Density ◽  
Zero Point ◽  
Scalar Fields ◽  
Flat Space ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Zero Point Energy ◽  
Point Energy ◽  
Renormalized Energy

The renormalized energy density of a massless scalar field defined in a D-dimensional flat space–time is computed in the presence of "soft" and "semihard" boundaries, modeled by some smoothly increasing potential functions. The sign of the renormalized energy densities for these different confining situations is investigated. The dependence of this energy on D for the cases of "hard" and "soft/semihard" boundaries are compared.

Joule–Thomson expansion and quasinormal modes of regular non-minimal magnetic black hole

2020 ◽  
Vol 35 (36) ◽  
pp. 2050298
Author(s):  
Abdul Jawad ◽  
Muhammad Yasir ◽  
Shamaila Rani
Keyword(s):  
Black Hole ◽  
Mass Formula ◽  
Quasinormal Modes ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Thomson Effect ◽  
First Order ◽  
Thermodynamical Parameters ◽  
Klein Gordon ◽  
Tortoise Coordinate

The Joule–Thomson effect and quasinormal modes (QNM) onto regular non-minimal magnetic charged black hole with a cosmological constant are being investigated. For this purpose, we extract some thermodynamical parameters such as pressure [Formula: see text] and mass [Formula: see text] in the presence of magnetic [Formula: see text] as well as electric [Formula: see text] charge. These parameters lead to inversion temperature [Formula: see text], pressure [Formula: see text] and corresponding isenthalpic curves. We introduce the tortoise coordinate and the Klein–Gordon wave equation which leads to the second-order ordinary Schrödinger equation. We find out the complex frequencies of QNMs through the massless scalar field perturbation which satisfy boundary conditions by using the first-order Wentzel–Kramers–Brillouin (WKB) technique.

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