scholarly journals Influence of quantized massive matter fields on the Casimir effect

2015 ◽  
Vol 30 (20) ◽  
pp. 1550099
Author(s):  
Yu. A. Sitenko
Keyword(s):  
Magnetic Field ◽  
Casimir Effect ◽  
Hamiltonian Operator ◽  
Matter Field ◽  
Parallel Plates ◽  
Vacuum Fluctuations ◽  
New Type ◽  
The Magnetic Field ◽  
External Uniform Magnetic Field ◽  
Matter Fields

Charged massive matter fields of spin-0 and spin-[Formula: see text] are quantized in the presence of an external uniform magnetic field in a spatial region bounded by two parallel plates. The most general set of boundary conditions at the plates, that is required by mathematical consistency and the self-adjointness of the Hamiltonian operator, is employed. The vacuum fluctuations of the matter field in the case of the magnetic field orthogonal to the plates are analyzed, and it is shown that the pressure from the vacuum onto the plates is positive and independent of the boundary condition, as well as of the distance between the plates. Possibilities of the detection of this new-type Casimir effect are discussed.

scholarly journals Magnetic field corrections to the repulsive Casimir effect at finite temperature

2016 ◽  
Vol 31 (07) ◽  
pp. 1650018 ◽  
Author(s):  
Andrea Erdas
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
High Temperature ◽  
Finite Temperature ◽  
Casimir Effect ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Parallel Plates ◽  
The Magnetic Field ◽  
Plate Distance

I investigate the finite temperature Casimir effect for a charged and massless scalar field satisfying mixed (Dirichlet–Neumann) boundary conditions on a pair of plane parallel plates of infinite size. The effect of a uniform magnetic field, perpendicular to the plates, on the Helmholtz free energy and Casimir pressure is studied. The [Formula: see text]-function regularization technique is used to obtain finite results. Simple analytic expressions are obtained for the zeta function and the free energy, in the limits of small plate distance, high temperature and strong magnetic field. The Casimir pressure is obtained in each of the three limits and the situation of a magnetic field present between and outside the plates, as well as that of a magnetic field present only between the plates is examined. It is discovered that, in the small plate distance and high temperature limits, the repulsive pressure is less when the magnetic field is present between the plates but not outside, than it is when the magnetic field is present between and outside the plates.

scholarly journals Radio Emission Model of a 'Typical' Pulsar

1987 ◽  
Vol 40 (6) ◽  
pp. 755 ◽  
Author(s):  
AZ Kazbegi ◽  
GZ Machabeli ◽  
G Melikidze
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Waves ◽  
Emission Model ◽  
Radio Waves ◽  
Resonance Case ◽  
Pulsar Magnetosphere ◽  
Pulsar Emission ◽  
Dipole Magnetic Field ◽  
New Type ◽  
The Magnetic Field

The generation of radio waves in the plasma of the pulsar magnetosphere is considered taking into account the inhomogeneity of the dipole magnetic field. It is shown that the growth rate of the instability of the electromagnetic waves calculated in the non-resonance case turns out to be of the order of 1/ TO (where TO is the time of plasma escape from the light cylinder). However, the generation of electromagnetic waves from a new type Cherenkov resonance is possible, occurring when the particles have transverse velocities caused by the drift due to the inhomogeneity of the magnetic field. Estimates show that the development of this type of instability is possible only for pulsars with ages which exceed 104 yr. We make an attempt to explain some peculiarities of 'typical' pulsar emission on the basis of the model developed.

scholarly journals The Casimir effect with quantized charged scalar matter in background magnetic field

2014 ◽  
Vol 29 (09) ◽  
pp. 1450052 ◽  
Author(s):  
Yu. A. Sitenko ◽  
S. A. Yushchenko
Keyword(s):  
Magnetic Field ◽  
Boundary Condition ◽  
Boundary Conditions ◽  
Casimir Force ◽  
Matter Field ◽  
Particle Energy ◽  
Parallel Plates ◽  
Charged Scalar ◽  
Scalar Matter ◽  
Background Magnetic Field

We study the influence of a background uniform magnetic field and boundary conditions on the vacuum of a quantized charged massive scalar matter field confined between two parallel plates; the magnetic field is directed orthogonally to the plates. The admissible set of boundary conditions at the plates is determined by the requirement that the operator of one-particle energy squared be self-adjoint and positive-definite. We show that, in the case of a weak magnetic field and a small separation of the plates, the Casimir force is either attractive or repulsive, depending on the choice of a boundary condition. In the case of a strong magnetic field and a large separation of the plates, the Casimir force is repulsive, being independent of the choice of a boundary condition, as well as of the distance between the plates.

A New Type of Oscillations in Germanium under the Magnetic Field

1964 ◽  
Vol 3 (2) ◽  
pp. 72-81 ◽  
Author(s):  
Kiichi Komatsubara ◽  
Noboru Takasugi ◽  
Hirokazu Kurono
Keyword(s):  
Magnetic Field ◽  
New Type ◽  
The Magnetic Field

scholarly journals Magnetohydrodynamic evolution of magnetic skeletons

2007 ◽  
Vol 463 (2080) ◽  
pp. 1097-1115 ◽  
Author(s):  
Andrew L Haynes ◽  
Clare E Parnell ◽  
Klaus Galsgaard ◽  
Eric R Priest
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Three Dimensional ◽  
Heating Process ◽  
Initial State ◽  
Fundamental Building Block ◽  
New Type ◽  
Field Lines ◽  
First Time ◽  
The Magnetic Field

The heating of the solar corona is probably due to reconnection of the highly complex magnetic field that threads throughout its volume. We have run a numerical experiment of an elementary interaction between the magnetic field of two photospheric sources in an overlying field that represents a fundamental building block of the coronal heating process. The key to explaining where, how and how much energy is released during such an interaction is to calculate the resulting evolution of the magnetic skeleton. A skeleton is essentially the web of magnetic flux surfaces (called separatrix surfaces) that separate the coronal volume into topologically distinct parts. For the first time, the skeleton of the magnetic field in a three-dimensional numerical magnetohydrodynamic experiment is calculated and carefully analysed, as are the ways in which it bifurcates into different topologies. A change in topology normally changes the number of magnetic reconnection sites. In our experiment, the magnetic field evolves through a total of six distinct topologies. Initially, no magnetic flux joins the two sources. Then, a new type of bifurcation, called a global double-separator bifurcation , takes place. This bifurcation is probably one of the main ways in which new separators are created in the corona (separators are field lines at which three-dimensional reconnection takes place). This is the first of five bifurcations in which the skeleton becomes progressively more complex before simplifying. Surprisingly, for such a simple initial state, at the peak of complexity there are five separators and eight flux domains present.

scholarly journals New Superconductivity and Theoretical Study on a New Phenomenon of Energy Source with Assistance of Initial Experiments

2018 ◽  
Author(s):  
Shinichi Ishiguri
Keyword(s):  
Magnetic Field ◽  
Energy Source ◽  
Electrostatic Field ◽  
Theoretical Study ◽  
Depletion Layer ◽  
Field Energy ◽  
Magnetic Field Energy ◽  
New Type ◽  
The Magnetic Field ◽  
A Current

We previously reported new superconductivity produced by an electrostatic field and a diffusion current in a semiconductor without refrigeration. In particular, the superconductivity was investigated theoretically and confirmed experimentally. Here, we determine that the derived superconducting quantum state can be reproduced in a capacitor. When circuits are formed with this new-type capacitor and diodes, a magnetic field is applied to the diodes’ depletion layer. The depletion layer is biased because of the conversion from the magnetic-field energy to electric-field energy, resulting in the diodes’ spontaneously emitting a current. Thus, the new-type capacitor is charged using no other energy source. This new phenomenon is described theoretically with assistance of initial experiments.

Magnetohydrodynamic Moving Liquid Plug Within a Microchannel: Analytical Solutions

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Mustafa Turkyilmazoglu
Keyword(s):  
Magnetic Field ◽  
Analytical Study ◽  
Circulation Rate ◽  
Axial Flux ◽  
Science And Engineering ◽  
Mixing Properties ◽  
Liquid Plug ◽  
The Magnetic Field ◽  
External Uniform Magnetic Field ◽  
Moving Liquid

Abstract The wide applications of plug flows in microscale in science and engineering help them attract a great deal recent interest. An analytical study is undertaken here to study the impacts of a transversely applied external uniform magnetic field affecting the motion of liquid in the plug in terms of hydrodynamic mixing properties. The well-known symmetric vortex structure occurring in a long plug with moderate aspect ratio is observed to be preserved, while the recirculation phenomenon is highly affected by the action of the magnetic field. The decelerating feature of Lorentz force on the liquid motion is illuminated by reducing the strength of the recirculating vortex moving towards the upper and lower walls. The effects of magnetic field on the flow resistance of the liquid plug as well as on the plug circulation rate and on the axial flux are also clarified. The liquid plug considered here is shown to be fully consistent with the continuous liquid flow in a channel whose exact solution is further extracted.

The roller chain lubricated with ferrofluids

2018 ◽  
Vol 233 (6) ◽  
pp. 927-935
Author(s):  
Yanjuan Zhang ◽  
Zhengqing Yang ◽  
Decai Li
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Service Life ◽  
Chain Structure ◽  
Lubricating Oil ◽  
Roller Chain ◽  
New Type ◽  
Chain Transmission ◽  
Novel Method ◽  
The Magnetic Field

The sleeve of roller chain periodically squeezes the pin during the process of chain transmission. The lubrication oil located in the gap of the sleeve and pin will be pushed out and cannot be restored automatically. The absence of sufficient lubricating oil can cause friction, wear, and even the roller chain failure between the pin and the sleeve. This article presents a novel method and a new type of chain structure to lubricant roller chain with ferrofluids, which is capable of prolonging the service life of roller chain. The results show that ferrofluids can be remained in the clearance between the sleeve and the pin shaft under the effect of external magnetic field. The ferrofluids that were squeezed out of the clearance can be restored automatically, which ensure the reliability of chain transmission. And the external magnetic field effectively prevents the chain lubrication leakage due to the edge effect of the magnetic field.

scholarly journals Effects of Quantum Fields Outside Cosmic Strings

1988 ◽  
Vol 130 ◽  
pp. 565-565
Author(s):  
D. A. Konkowski ◽  
T. M. Helliwell
Keyword(s):  
Cosmic String ◽  
Casimir Effect ◽  
Semiclassical Approximation ◽  
Mass Density ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Energy Tensor ◽  
Parallel Plates ◽  
Vacuum Fluctuations ◽  
Gravitational Influence

The space surrounding a long straight cosmic string is flat but conical. The conical topology implies that such a string focuses light rays or particles passing by opposite sides of the string, which can have important astrophysical effects. The flatness, however, implies that the string has no gravitational influence on matter at rest with respect to the string. The flatness is a consequence of the fact that the tension along a cosmic string is equal to its linear mass density μ. There may be physical effects, however, which destroy the equality of tension and mass density, so that straight strings might after all affect matter at rest. One such effect we and others have calculated is the vacuum fluctuations of fields near the strings induced by the conical topology. Such fluctuation s are physically observable but normally small, as in the Casimir effect between parallel plates. We find the vacuum expectation value of the stress - energy tensor of a conformally coupled scalar field around a cosmic string to be in cylindrical coordinates (t, r, θ, z). The equality of Ttt and Tzz means that the effective tension and mass density of the vacuum fluctuations are equal, so that at least in a semiclassical approximation a string dressed by such fields still has no gravitational influence on matter at rest, even though it has a substantial mass density.

Sign in / Sign up

Export Citation Format

Share Document