Table of contents

Recent theoretical work concerning the magnetosphere of and radio emission from pulsars is reviewed in detail. Taking into account years of little or no cooperation between theory and observation and noting, in particular, that no systematic observations are in fact being made to check theoretical predictions, the key ideas underlying the theory of the pulsar magnetosphere are formulated and new observations aimed at verifying current models are discussed.

The problem of infrared and collinear divergences is considered within the framework of perturbation theory and the scattering operator redefinition method. IR divergent processes in electrodynamics and gravitation (perturbation theory) are described, and for the case of electrodynamics a scattering operator free from IR divergences is constructed. For the massless electrodynamics model, a recipe for constructing a scattering operator free from both IR and collinear divergences is given. The meaning of experimental parameters entering the final formulas is discussed, and it is shown that the S-matrix factorization (i.e., the approximate independence of hard and soft processes) makes the theorem on the cancellation of divergences in observables trivial. A method for finding divergences in theories with multiparticle vertices is presented.

Experimental and theoretical work on solid hydrogen under high pressure is reviewed with special emphasis on three aspects of the field. The first concerns the equation of state of hydrogen and the properties of its molecular phase. Both experimental and theoretical studies show that hydrogen has a rich variety of unusual properties even in its molecular phase, as the formation of many highly anisotropic crystal structures with little energy difference exemplifies. The second aspect is the insulator-metal transition which, while customarily associated with atomization, i.e., with the dissociation of hydrogen molecules, is also possible in the molecular phase according to recent theoretical studies. In discussing the metallic phase, finally, the existence of a metastable phase at normal pressure and prospects for the high superconducting transition temperatures in metallic hydrogen are considered.

The state of the art in the modification of iron, steel, and titanium alloys and some metal multilayers by medium intensity (10⁶–10⁹ W cm⁻²) pulsed electron and ion beams is summarized, including the contribution from the authors. Many of the processes that determine the defect structure and its properties are described and such problems as the formation of elastoplastic and shock waves, mixing of multilayers, thin film deposition, and nanophase powder synthesis are discussed. The high potential of particle beam technology — in particular, for improving the operating characteristics of materials — has been demonstrated amply by research centers worldwide.

The problem of copying a polyatomic system is analyzed from first principles quantum mechanically to show the number of minima of the adiabatic electron term to be the factor determining the storage capacity.