Table of contents

This review analyzes radiation produced by randomly inhomogeneous media excited by fast particles — i.e., polarization bremsstrahlung for thermodynamically equilibrium inhomogeneities or transition radiation for nonthermal ones — taking into account all the effects important for natural sources. Magnetic field effects on both the motion of fast particles and the dispersion of background plasma are considered, and the multiple scattering of fast particles in the medium is examined. Various resonant effects occurring under the conditions of Cherenkov (or cyclotron) emission for a particular eigenmode are discussed. The transition radiation intensity and absorption (amplification) coefficients are calculated for ensembles of fast particles with realistic distributions over momentum and angles. The value of the developed theory of transition radiation is illustrated by applying it to astrophysical objects. Transition radiation is shown to contribute significantly to the radio emission of the Sun, planets (including Earth), and interplanetary and interstellar media. Possible further applications of transition radiation (particularly stimulated) are discussed.

Physical mechanisms and theoretical models of laser ablation are discussed. For various mechanisms, typical associated phenomena are qualitatively regarded and methods for studying them quantitatively are considered. Calculated results relevant to ablation kinetics for a number of substances are presented and compared with experimental data.

The advantages and peculiarities of the variational method of solving electrostatic problems are clearly illustrated using the ground resistance as a relatively simple example.

A comparative analysis of various forms of the Maxwell equations for condensed matter is presented. It is shown that the so-called Casimir form contains enough information to solve any electromagnetic problem. The Landau–Lifshitz form intended for describing media with spatial dispersion requires an additional constitutive equation for the surface current, which does not set an additional boundary condition but acts as a replacement of usual Maxwell's continuity conditions for tangential field components.