Magnetostatics of thin wires is a specific branch of theoretical physics. Its main equation always contains a source, which can only be an endless curve in form. The field of an arc, which has endpoints, is not defined, therefore, there exists only entire field of an entire endless wire. This feature of the subject does not allow to employ the method of Green's functions, which requires that a wire is divided into small pieces. Therefore, only entire filed of an endless wire exists, therefore, such a wire plays the role of the "elementary" source. In this book an approach is outlined, which...

Galaxies and star clusters are collisionless self- gravitating systems. The models of their equilibrium states are solutions of the corresponding equations based on equations of motion of the particles of which the system consists. Therefore, modeling these systems requires solution of a series of problems, starting from the one-body problem. In this book models of various axially-symmetric collisionless systems are built, among which there are thin disk, bulge of a spiral galaxy and prolate galaxy in equilibrium and evolutionary states.