I. P. Denisova

Verifiable Post-Maxwellian Effect of the Nonlinear Electrodynamics in Vacuum

The lasing frequencies of a ring laser with counterpropagating electromagnetic waves are calculated for the case when a part of the laser circuit is subjected to a constant electromagnetic field. It is demonstrated that, according to equations of the parametrized post-Maxwellian electrodynamics of vacuum, two waves with different planes of polarization and frequencies should propagate in each direction of the ring laser. The analysis has shown that, with the help of advanced ring lasers and external electromagnetic fields attainable in the laboratory, the post-Maxwellian parameters can be measured with a precision that would be sufficient to verify the most popular theoretical models of the nonlinear electrodynamics of vacuum.

Interaction of intense laser radiation with weak electromagnetic waves in an evacuated section of a ring laser

A laboratory experiment for the study of nonlinear interaction of electromagnetic waves in vacuum is proposed. The basic idea of the experiment is as follows. If one separates a certain region of the circuit in a ring laser from the remaining part with gas-impenetrable partitions, evacuates it, and forms external electromagnetic fields there, the oscillation frequencies and the polarization states of the electromagnetic waves traveling in this ring laser in counter directions are different. A calculation is made for the oscillation frequencies of electromagnetic waves traveling in a ring laser in opposite directions in the case when they interact in an evacuated section of the ring laser circuit with intense laser radiation. It is shown that the effect can be observed in experiments using presently available pulsed lasers of ultrahigh power.

Nonlinear electrodynamic lag of electromagnetic signals in a magnetic dipole field

We investigate the propagation of electromagnetic waves in the magnetic dipole and gravitational fields of a neutron star, which follows the laws of nonlinear electrodynamics in a vacuum. Electromagnetic signals in these fields are shown to propagate along different rays and at different velocities, depending on their polarization. We found the law of motion for these signals along rays. We calculate the difference between the propagation times of electromagnetic signals with different polarizations from the same source to the detector. This difference is shown to reach a measurable value of 1 μs in some cases.

Nonlinear electrodynamic effect of ray bending in the magnetic-dipole field

For a long time, nonlinear electrodynamics in vacuum had no experimental verification and, therefore, was considered by many researchers as an abstract theoretical model. At present, its status has changed essentially. Experiments [1] on the inelastic scattering of laser photons by gamma photons corroborated that the electrodynamics in vacuum is actually a nonlinear theory. Therefore, its various predictions, which can be verified experimentally, are worthy of the most serious attention. rotH 1 c --∂D ∂t -----, divD 0, = =

Nonlinear Electrodynamic Delay of Electromagnetic Signals in a Coulomb Field

We study the motion of electromagnetic signals in the Coulomb electric field of a compact gravitating center under the laws of the parameterized nonlinear electrodynamics of the vacuum. We evaluate the deflection angles of the rays along which the electromagnetic waves of two normal modes propagate in this field. We determine the nonlinear electrodynamic delay of the electromagnetic signal of one normal mode relative to the electromagnetic signal of another normal mode during their propagation from the same source to an observer.

Nonlinear electromagnetic delay of electromagnetic signals in the magnetic field of a neutron star

Interest in the nonlinear electrodynamics of vacuum has been recently renewed [1, 2], because the sensitivity of current measuring instruments has closely approached the level that is required for detecting its effects [3, 4]. Therefore, after the first nonlinear electrodynamic experiment [5] recently carried out in Stanford, other experiments should follow in the near future that will make it possible to study the basic properties of the nonlinear interaction of electromagnetic fields in vacuum.

Optical nonreciprocity in a magnetically active isotropic medium

The complex permittivity tensor of a magnetically active isotropic medium is expanded, to third-order accuracy, in terms of a small parameter equal to the ratio of the mean distance between the atoms of the medium to the wavelength of an electromagnetic wave. A dispersion equation is constructed. On the basis of this equation, the refractive indices of the medium for normal waves are obtained when a longitudinal magnetic field is applied to the medium. It is shown that calculations to third-order accuracy yield different values for the velocities of all four normal waves that propagate in the medium in forward and backward directions. Calculations are carried out for the experiment conducted with the use of a ring laser for measuring the expansion coefficients of the complex permittivity tensor that are responsible for the small difference between the velocities of the normal waves propagating in forward and backward directions. It is shown that, in the case of an isotropic optically nonactive medium, the third-order expansion coefficients can be measured by means of a ring laser with an absolute accuracy on the order of 10−14.

Locally Optimal Laws of Control of a Spacecraft Motion with an Electrodynamic Engine at Circumterrestrial Orbits

The motion of a spacecraft under the action of Ampére force is investigated. This force arises as a result of the interaction of the current in a rigid rod, at whose ends the devices which close the electric circuit through the circumterrestrial plasma are located, with the magnetic field of the Earth. The locally optimal laws of control by this rod orientation are found, when one of the elements of the orbit gains the maximum increment under the action of this engine. Numerical estimates of the gained increments are obtained, and it is demonstrated that this engine is a promising tool for the execution of light spacecraft maneuvers at low circumterrestrial orbits.

On the constraint equation in the relativistic theory of gravitation

Expressions for covariant and contravariant components of the metric tensor for the effective Riemann space-time and for its determinant are constructed on the basis of the relations of tensor algebra.