Table of contents

Recent studies of finite-size effects in charge-density wave conductors are reviewed. Various manifestations of finite-size effects, including the transverse-size dependence of the nonlinear-conduction threshold field, the Peierls transition temperature, high-frequency conduction, and the relaxation rates of metastable states, are discussed. Resistivity jumps in thin samples, the smeared threshold field for nonlinear conduction, and threshold conduction above the Peierls transition temperature are considered, as are mesoscopic oscillations of the threshold field, one-dimensional conduction in thin crystals, absolute negative conductivity of quasi-one-dimensional conductors, the length dependence of the phase-slip voltage, and the Aharonov–Bohm oscillations in sliding CDWs. Problems yet to be solved are discussed.

Electromagnetic waves in a plasma in a magnetic field give rise to enhanced refraction, produce a change in polarization, and cause electromagnetic energy to flow from one wave mode to another when propagating near the critical surface (CS), the one where the electron Langmuir frequency is equal to the wave frequency. A simple unified model of all phenomena taking place near the CS is proposed. These phenomena are due to electromagnetic waves linearly interacting with electron Langmuir oscillations which are localized at the CS in a cold plasma. This interaction manifests itself most strikingly in electron Langmuir oscillation energy escaping directly into a vacuum in the form of electromagnetic radiation.

Optimal control theory-based methods for improving the efficiency of Cherenkov microwave amplifiers with irregular electrodynamic structures are reviewed. The physics of optimal processes in amplifiers and oscillators with Cherenkov- and combined-type interactions is discussed.

Refraction of a slow surface electromagnetic wave (magnetostatic wave) at the boundary between ferrite and ferrite-insulator-metal media is investigated experimentally and theoretically. The boundary is created in an yttrium iron garnet film by placing a metal plate at a certain distance from its surface. The refractive index is found to depend on the angle of incidence of the wave and can take on any positive or negative values. It is shown that in anisotropic media, in particular, in ferromagnets, due to the noncollinearity of the wave vector and the group velocity vector, negative refraction can occur not only in the earlier predicted case where the incident wave is forward and the refracted wave is backward, but also in the case where both waves are forward.

The ways in which Albert Einstein and David Hilbert independently arrived at the gravitational field equations are traced. A critical analysis is presented of a number of papers in which the history of the derivation of the equations is viewed in a way that "radically differs from the standard point of view." The conclusions of these papers are shown to be totally unfounded.