scholarly journals CASIMIR ENERGY DENSITY IN CLOSED HYPERBOLIC UNIVERSES

2002 ◽  
Vol 17 (29) ◽  
pp. 4385-4392 ◽  
Author(s):  
DANIEL MÜLLER ◽  
HELIO V. FAGUNDES
Keyword(s):  
Electromagnetic Field ◽  
Scalar Field ◽  
Energy Density ◽  
Boundary Conditions ◽  
Negative Curvature ◽  
Casimir Effect ◽  
Casimir Energy ◽  
The Difference

The original Casimir effect results from the difference in the vacuum energies of the electromagnetic field, between that in a region of space with boundary conditions and that in the same region without boundary conditions. In this paper we develop the theory of a similar situation, involving a scalar field in spacetimes with closed spatial sections of negative curvature.

Electromagnetic thermal corrections to Casimir energy

2016 ◽  
Vol 31 (22) ◽  
pp. 1650127 ◽  
Author(s):  
Borzoo Nazari
Keyword(s):  
Electromagnetic Field ◽  
Gravitational Field ◽  
Scalar Field ◽  
Finite Temperature ◽  
Casimir Effect ◽  
Casimir Energy ◽  
Parallel Plates ◽  
Weak Gravitational Field

In [B. Nazari, Mod. Phys. Lett. A 31, 1650007 (2016)], we calculated finite temperature corrections to the energy of the Casimir effect of two conducting parallel plates in a general weak gravitational field. The calculations was done for the case a scalar field was present between the plates. Here we find the same results in the presence of an electromagnetic field.

scholarly journals Comments on “Casimir effect in the Kerr spacetime with quintessence”

2017 ◽  
Vol 32 (21) ◽  
pp. 1775001 ◽  
Author(s):  
Bobir Toshmatov ◽  
Zdeněk Stuchlík ◽  
Bobomurat Ahmedov
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Casimir Effect ◽  
Kerr Black Hole ◽  
Casimir Energy ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Kerr Spacetime ◽  
The Difference

This comment is devoted to the recalculation of the Casimir energy of a massless scalar field in the Kerr black hole surrounded by quintessence derived in [B. Toshmatov, Z. Stuchlík and B. Ahmedov, Eur. Phys. J. Plus 132, 98 (2017)] and its comparison with the results recently obtained in [V. B. Bezerra, M. S. Cunha, L. F. F. Freitas and C. R. Muniz, Mod. Phys. Lett. A 32, 1750005 (2017)] in the spacetime [S. G. Ghosh, Eur. Phys. J. C 76, 222 (2016)]. We have shown that in the more realistic spacetime which does not have the failures illustrated here, the Casimir energy is significantly bigger than that derived in [V. B. Bezerra, M. S. Cunha, L. F. F. Freitas and C. R. Muniz, Mod. Phys. Lett. A 32, 1750005 (2017)], and the difference becomes crucial especially in the regions of near horizons of the spacetime.

ON THE SCALAR CASIMIR ENERGIES IN SPACE-TIMES WITH Md × Tq STRUCTURE

1991 ◽  
Vol 06 (20) ◽  
pp. 1855-1861 ◽  
Author(s):  
F. CARUSO ◽  
N. P. NETO ◽  
B. F. SVAITER ◽  
N. F. SVAITER
Keyword(s):  
Scalar Field ◽  
Energy Density ◽  
Boundary Conditions ◽  
Periodic Boundary ◽  
Periodic Boundary Conditions ◽  
Casimir Energy ◽  
Space Time ◽  
Time Dimension

The Casimir energy density of a scalar field quantized in a Md × Tq space-time is calculated. The field is supposed to satisfy Dirichlet and periodic boundary conditions in the (d − 1)- and q-dimensional submanifolds respectively. On account of this non-trivial topology, the sign of the Casimir energy is shown to have the same peculiar and entangled dependence on the number of finite sides of the hyperparallelopipedal cavity and on the space-time dimension, with only one exception which is discussed.

scholarly journals Casimir effect of a Lorentz-violating scalar in magnetic field

2020 ◽  
Vol 35 (31) ◽  
pp. 2050209
Author(s):  
Andrea Erdas
Keyword(s):  
Magnetic Field ◽  
Scalar Field ◽  
Boundary Conditions ◽  
Casimir Effect ◽  
Lorentz Invariance ◽  
Neumann Boundary ◽  
Casimir Energy ◽  
Neumann Boundary Conditions ◽  
Parallel Plates ◽  
Massive Scalar Field

In this paper, I study the Casimir effect caused by a charged and massive scalar field that breaks Lorentz invariance in a CPT-even, aether-like manner. I investigate the case of a scalar field that satisfies Dirichlet or mixed (Dirichlet–Neumann) boundary conditions on a pair of very large plane parallel plates. The case of Neumann boundary conditions is straightforward and will not be examined in detail. I use the [Formula: see text]-function regularization technique to study the effect of a constant magnetic field, orthogonal to the plates, on the Casimir energy and pressure. I investigate the cases of a timelike Lorentz asymmetry, a spacelike Lorentz asymmetry in the direction perpendicular to the plates, and a spacelike asymmetry in the plane of the plates and, in all those cases, derive simple analytic expressions for the zeta function, Casimir energy and pressure in the limits of small plate distance, strong magnetic field and large scalar field mass. I discover that the Casimir energy and pressure, and their magnetic corrections, all strongly depend on the direction of the unit vector that implements the breaking of the Lorentz symmetry.

scholarly journals Casimir effect with one large extra dimension

2021 ◽  
Author(s):  
Andrea Erdas
Keyword(s):  
Scalar Field ◽  
Boundary Conditions ◽  
Extra Dimension ◽  
Casimir Effect ◽  
Neumann Boundary ◽  
Casimir Energy ◽  
Neumann Boundary Conditions ◽  
Three Dimensions ◽  
Parallel Plates ◽  
Large Extra Dimension

In this work, I study the Casimir effect of a massive complex scalar field in the presence of one large compactified extra dimension. I investigate the case of a scalar field confined between two parallel plates in the macroscopic three dimensions, and examine the cases of Dirichlet and mixed (Dirichlet–Neumann) boundary conditions on the plates. The case of Neumann boundary conditions is uninteresting, since it yields the same result as the case of Dirichlet boundary conditions. The scalar field also permeates a fourth compactified dimension of a size that could be comparable to the distance between the plates. This investigation is carried out using the [Formula: see text]-function regularization technique that allows me to obtain exact expressions for the Casimir energy and pressure. I discover that when the compactified length of the extra dimension is similar to the plate distance, or slightly larger, the Casimir energy and pressure become significantly different than their standard three-dimensional values, for either Dirichlet or mixed boundary conditions. Therefore, the Casimir effect of a quantum field that permeates a compactified fourth dimension could be used as an effective tool to explore the existence of large compactified extra dimensions.

scholarly journals SCALAR CASIMIR EFFECT BETWEEN TWO CONCENTRIC D-DIMENSIONAL SPHERES

2012 ◽  
Vol 27 (18) ◽  
pp. 1250094 ◽  
Author(s):  
MUSTAFA ÖZCAN
Keyword(s):  
Scalar Field ◽  
Boundary Conditions ◽  
Complex Plane ◽  
Casimir Force ◽  
Dirichlet Boundary ◽  
Casimir Effect ◽  
Casimir Energy ◽  
Dirichlet Boundary Conditions ◽  
Massless Scalar ◽  
Massless Scalar Field

The Casimir energy for a massless scalar field between the closely spaced two concentric D-dimensional (for D>3) spheres is calculated by using the mode summation with contour integration in the complex plane of eigenfrequencies and the generalized Abel–Plana formula for evenly spaced eigenfrequency at large argument. The sign of the Casimir energy between closely spaced two concentric D-dimensional spheres for a massless scalar field satisfying the Dirichlet boundary conditions is strictly negative. The Casimir energy between (D-1)-dimensional surfaces, close to each other is regarded as interesting both by itself and as the key to describing of stability of the attractive Casimir force.

scholarly journals Casimir effect for a massive scalar field under mixed boundary conditions

2003 ◽  
Vol 33 (4) ◽  
pp. 860-866 ◽  
Author(s):  
A.C. Aguiar Pinto ◽  
T.M. Britto ◽  
R. Bunchaft ◽  
F. Pascoal ◽  
F.S.S. da Rosa
Keyword(s):  
Scalar Field ◽  
Boundary Conditions ◽  
Mixed Boundary ◽  
Casimir Effect ◽  
Mixed Boundary Conditions ◽  
Massive Scalar ◽  
Massive Scalar Field

Finite-Péclet-number effects on the scaling exponents of high-order passive scalar structure functions

2012 ◽  
Vol 713 ◽  
pp. 453-481 ◽  
Author(s):  
J. Lepore ◽  
L. Mydlarski
Keyword(s):  
Scalar Field ◽  
Boundary Conditions ◽  
Passive Scalar ◽  
Structure Functions ◽  
High Order ◽  
Field Boundary ◽  
Scaling Exponents ◽  
Heated Cylinder ◽  
Scalar Structure ◽  
The Difference

AbstractThe effect of scalar-field (temperature) boundary conditions on the inertial-convective-range scaling exponents of the high-order passive scalar structure functions is studied in the turbulent, heated wake downstream of a circular cylinder. The temperature field is generated two ways: using (i) a heating element embedded within the cylinder that generates the hydrodynamic wake (thus creating a heated cylinder) and (ii) a mandoline (an array of fine, heated wires) installed downstream of the cylinder. The hydrodynamic field is independent of the scalar-field boundary conditions/injection methods, and the same in both flows. Using the two heat injection mechanisms outlined above, the inertial-convective-range scaling exponents of the high-order passive scalar structure functions were measured. It is observed that the different scalar-field boundary conditions yield significantly different scaling exponents (with the magnitude of the difference increasing with structure function order). Moreover, the exponents obtained from the mandoline experiment are smaller than the analogous exponents from the heated cylinder experiment (both of which exhibit a significant departure from the Kolmogorov prediction). Since the observed deviation from the Kolmogorov $n/ 3$ prediction arises due to the effects of internal intermittency, the typical interpretation of this result would be that the scalar field downstream of the mandoline is more internally intermittent than that generated by the heated cylinder. However, additional measures of internal intermittency (namely the inertial-convective-range scaling exponents of the mixed, sixth-order, velocity–temperature structure functions and the non-centred autocorrelations of the dissipation rate of scalar variance) suggest that both scalar fields possess similar levels of internal intermittency – a distinctly different conclusion. Examination of the normalized high-order moments reveals that the smaller scaling exponents (of the high-order passive scalar structure functions) obtained for the mandoline experiment arise due to the smaller thermal integral length scale of the flow (i.e. the narrower inertial-convective subrange) and are not solely the result of a more intermittent scalar field. The difference in the passive scalar structure function scaling exponents can therefore be interpreted as an artifact of the different, finite Péclet numbers of the flows under consideration – an effect that is notably less prominent in the other measures of internal intermittency.

scholarly journals The Casimir effect for thick pistons

2016 ◽  
Vol 31 (06) ◽  
pp. 1650012
Author(s):  
Guglielmo Fucci
Keyword(s):  
Boundary Conditions ◽  
Zeta Function ◽  
Regularization Method ◽  
Casimir Force ◽  
Casimir Effect ◽  
Casimir Energy ◽  
Numerical Results ◽  
Spectral Zeta Function

In this work, we analyze the Casimir energy and force for a thick piston configuration. This study is performed by utilizing the spectral zeta function regularization method. The results we obtain for the Casimir energy and force depend explicitly on the parameters that describe the general self-adjoint boundary conditions imposed. Numerical results for the Casimir force are provided for specific types of boundary conditions and are also compared to the corresponding force on an infinitely thin piston.

scholarly journals On the Casimir energy of the electromagnetic field in the dispersive and absorptive medium

2014 ◽  
Vol 29 (18) ◽  
pp. 1450101
Author(s):  
M. A. Braun
Keyword(s):  
Dielectric Constant ◽  
Electromagnetic Field ◽  
Casimir Effect ◽  
Direct Interaction ◽  
Microscopic Theory ◽  
Casimir Energy ◽  
Indirect Interaction ◽  
One Dimensional ◽  
Absorptive Medium ◽  
The One

The microscopic theory of the Casimir effect in the dielectric is studied in the framework when absorption is realized via a reservoir modeled by a set of oscillators with continuously distributed frequencies with the aim to see if the effects depend on the form of interaction with the reservoir. A simple case of the one-dimensional dielectric between two metallic plates is considered. Two possible models are investigated, the direct interaction of the electromagnetic field with the reservoir and indirect interaction via an intermediate oscillator imitating the atom. It is found that with the same dielectric constant the Casimir effect is different in these two cases, which implies that in the second model it cannot be entirely expressed via the dielectric constant as in the well-known Lifshitz formula.

Sign in / Sign up

Export Citation Format

Share Document